JPH06270849A - Air spoiler device - Google Patents

Abstract

PURPOSE:To attain air resistance reduction consistently with down force securing. CONSTITUTION:At a body rear end 8 a main stream spoiler 15 is provided between intersections of right and left drawing lines 9 with the body rear end 8 and side stream spoilers 17 are provided at rear ends of right and left shelf- shape parts 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air spoiler device for improving aerodynamic characteristics of an automobile.

[0002]

2. Description of the Related Art A conventional air spoiler device of this type is shown in, for example, Japanese Patent Application Laid-Open No. 2-6281.
2 and FIG. 13 are available.

This is a fixed wing 103 fixed to the upper surface of the rear portion of the vehicle body, for example, the upper surface of the trunk lid panel 101 over the entire width in the left-right direction, and the fixed wing 10.
3 and a movable wing 105 that is rotatable with respect to FIG. The movable wing 105 is driven forward or backward by a command signal from a manual switch or a vehicle speed detector.
It is rotated along the movement locus determined through 1. The fixed wing 103 and the movable wing 105 form a variable blade cross section, and a predetermined downforce is obtained to improve aerodynamic characteristics.

[0004]

The air flow in the vicinity of the rear end of the vehicle body varies depending on the vehicle body shape, particularly the vehicle cabin part shape (so-called greenhouse shape).
The point is that the flow field is a mixture of triangular vortices generated in the front pillars of the vehicle and vortexes generated in the rear pillars. Specifically, it is divided into two mainstream and sidestream. The former (mainstream) flows linearly from the rear end of the roof to the rear end of the vehicle body on the rear end of the trunk lid or hatch gate where the air spoiler device is installed, and flows in the X direction (vehicle width direction) and Z direction.
The turbulence component due to the directional (vertical direction of the vehicle body) velocity component is large, and the total pressure loss (hydrodynamic energy loss of the flow) on the vehicle body surface is also large. The latter (sidestream) is bent at the rear pillar and has a streamline that matches the curvature, the turbulence component due to the velocity component in the X and Z directions is very small, and the total pressure loss on the vehicle body surface is also small. It is a flow.

In the conventional air spoiler device shown in FIGS. 12 and 13, the fixed wings 103 flow along the left and right rear pillar portions because the fixed wings 103 are provided over the entire vehicle width direction at the rear end of the vehicle body. Sidestream is fixed wing 103
Collide with the left and right ends of the
Behind 3, the flow separates. Due to this separation, the flow Y
The direction (front-rear direction) velocity component decreases, the X-direction or Y-direction velocity component relatively increases, the wake region where a large number of vortices are generated behind the vehicle body expands, and the air resistance C _D increases.

Further, the downforce obtained by the air spoiler device is obtained by increasing the air pressure at the rear of the spoiler to increase the pressure on the upper surface of the vehicle body as compared with that at the lower floor. The vehicle body upper surface pressure increases as the Z-direction velocity component of the air flow behind the spoiler increases. At this time, the Y-direction velocity component of the flow behind the spoiler becomes relatively small, and the air resistance C _D for making it easy to form a vortex behind the vehicle body becomes high.

Therefore, it is difficult to achieve both reduction in air resistance C _D and securing downforce.

[0008] Therefore, an object of the present invention is to provide an air spoiler device capable of achieving both reduction of air resistance and securing of downforce.

[0009]

In order to solve the above-mentioned problems, the invention of claim 1 is such that the height of the rear portion of the vehicle body is gradually reduced from the rear end of the roof to the rear end of the vehicle body. In the vehicle body structure, the lateral width of the outer surface of the rear pillar portion is formed to be gradually narrowed toward the rear end of the vehicle body, and the shelf-shaped portions extending to the vehicle body rear end are formed outside the left and right rear pillar portions in the vehicle width direction. A mainstream spoiler having a length in the vehicle width direction between the intersections of the extension lines of the rear pillars of the left and right rear pillars and the rear end lines of the vehicle body is provided at the rear ends of the vehicle body, and at the rear ends of the left and right shelf-like portions. It is characterized in that a side-stream spoiler having the right and left width of each of the shelves is provided.

According to a second aspect of the invention, there is provided the air spoiler device according to the first aspect, wherein the main stream spoiler and the sidestream spoiler are formed such that the height or elevation angle and sectional shape of the spoiler are different from each other. When a downforce of a predetermined value or less is obtained, only the sidestream spoiler is operated, and when a downforce of a predetermined value or more is desired, the mainstream spoiler is also operated.

According to a third aspect of the invention, there is provided the air spoiler device according to the first and second aspects, wherein the main-stream spoiler is based on a traveling state detecting means for detecting a traveling state of the vehicle and an output signal of the traveling state detecting means. And a control means for independently controlling the left and right sidestream spoilers.

According to the invention of claim 4, claims 1, 2 and 3 are provided.
The air spoiler device described above is characterized in that the spoiler height of the sidestream spoiler is set to a height within a total pressure loss region in a spoiler installation portion before installation of the spoiler.

[0013]

According to the first aspect of the invention, the mainstream spoiler provided at the rear portion of the vehicle body acts on the airflow flowing from the roof to the rear end of the vehicle body, and the sidestream spoiler is applied to the airflow flowing on the shelf. Can be operated.

According to the second aspect of the present invention, it is possible to have a state in which only the sidestream spoiler is operated and a state in which the mainstream spoiler is used together.

According to the third aspect of the invention, the traveling state of the vehicle can be detected by the traveling state detecting means, and the mainstream spoiler and the left and right sidestream spoilers can be controlled by the control means based on the detected traveling state. It is possible to obtain downforce according to the running condition.

According to the invention of claim 4, the spoiler height of the sidestream spoiler is set to a height within the total pressure loss region before installation of the spoiler, so that a high downforce can be obtained with a small air resistance.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a rear vehicle body equipped with an air spoiler device according to an embodiment of the present invention.

The vehicle body structure of this embodiment is a fastback, and the height of the rear portion of the vehicle body is gradually reduced from the rear end of the roof 1 to the rear end of the vehicle body. That is, the rear window portion 3 connected to the rear end of the roof 1
Are formed so as to gradually decrease toward the rear bumper 5 on the rear end 8 side of the vehicle body. Further, the rear pillar portion 7 provided on the rear portion of the vehicle body, that is, on the left and right of the rear window portion 3 is formed so that the left and right width gradually narrows toward a vehicle body rear end 8 along a predetermined diaphragm line 9. Further, on the left and right sides of the left and right rear pillar portions 7, substantially planar shelf-like portions 11 are formed extending along the diaphragm line 9 to the rear end 8 of the vehicle body. The shelf-like portion 11 is slightly inclined downward toward the outside in the vehicle width direction. An air spoiler device 13 is provided on the rear portion 8 of the vehicle body. The air spoiler device 13 includes a mainstream spoiler 15 provided at the rear end of the rear window portion 3 and left and right sidestream spoilers 17 provided at the rear ends of the left and right shelf portions 11. Mainstream air spoiler 15
Is the drawing line 9 of the left and right rear pillars 7 which is the length L in the vehicle width direction.
Is set to a length between intersections D and D of the extension line C of the vehicle body rear end line 8a, and the left and right sidestream spoilers 17 have a length 1 in the vehicle width direction of the left and right sides of the rear end of the vehicle body of the shelf-like portion 11. The width is set to the length.

The mainstream spoiler 15 is variably supported by supporting means so that it can be in two states, a non-acting state and a working state. That is, FIGS. 2 and 3 show the supporting means, and as shown in the figure, the mainstream spoiler 15 has a fixed wing 19 fixed to the panel upper surface at the rear of the vehicle body, and an elevation angle with respect to the fixed wing 19. It is composed of a changeable flat plate-shaped movable wing 21. Movable wing 21
Are supported by a pair of movable wing stays 23 fixed to the upper panel of the vehicle body via a drive link 25 and a driven link 27, respectively. That is, the bases of the drive link 25 and the driven link 27 are rotatably connected to the movable wing stays 23 by the fulcrum shafts 29 and 31, respectively, and the tip ends of the mounting brackets 33 and 35 fixed to the lower surface of the movable wing 21. Are rotatably connected to each other by mounting pins 37 and 39. Further, for example, a fluid pressure cylinder device 38 as an actuator is provided in the movable wing stay 23, and a contact pin 41 protruding from the tip end portion of the piston rod 40 of the fluid pressure cylinder 37 is formed on the drive link 25. It is movably engaged with the hole 43. The fluid pressure cylinder device 38 operates according to a command signal from a controller 45 as a control means, and the piston rod 40 expands and contracts to drive the drive link 25.
The movable wing 21 is rotated via the driven link 27 and the angle of attack thereof is changed. In addition, left and right side spoiler 1
7 is a wedge-shaped movable wing 47, as shown in FIG.
It is composed by. The movable wing 47 is rotatably supported by a stay 48 fixed to the upper surface of the shelf-like portion 11 via a fulcrum shaft 49, and also serves as an actuator, for example, a piston rod 53 of a fluid pressure cylinder device 51.
It is connected to the tip. This fluid pressure cylinder device 51
Is operated by a command signal from a controller 45 as a control means, and the movable wing 47 is rotated by expansion and contraction of the piston rod 53 to change the angle of attack thereof.

The controller 45 is composed of, for example, a microcomputer, and as shown in FIG. 5, a digital input detection circuit 55, a digital operation circuit 57, a storage circuit 59,
It has a digital / analog conversion circuit 61 and a drive circuit 63.

Further, the vehicle of this embodiment has a vehicle speed sensor 6 as a traveling state detecting means for detecting the traveling state of the vehicle.
5, steering angle sensor 67, yaw rate sensor 69 and lateral G
The sensor 71 is provided, and each sensor 65, 67, 69,
Reference numeral 71 is connected to the digital input detection circuit 55 of the controller 45. The vehicle speed sensor 65 detects the vehicle speed and outputs a signal V corresponding to the vehicle speed, the steering angle sensor 67 detects the steering angle and outputs a signal θ corresponding to the steering angle, and the yaw rate sensor 69 detects the yaw rate. A signal ψ corresponding to the yaw rate is output, and the lateral G sensor 71 detects the lateral G received by the vehicle to detect the lateral G.

[Outer 1] Next, the operation of the above embodiment will be described.

First, the air flow in the rear part of the vehicle body in the case where there is no left and right sidestream spoilers as shown in FIG. 6 in relation to the air flow in the vehicle body in this embodiment will be described.

First, triangular vortices E are generated in the left and right front pillar portions 73 of the vehicle body, and expand toward the rear of the vehicle body to pass through the left and right ends of the mainstream spoiler 15. Therefore, the air flow in the rear part of the vehicle body is sandwiched by the left and right triangular vortices E and flows from the roof 1 to the rear end of the vehicle body along the rear window part 3 and the left and right rear pillars outside the left and right triangular vortex E. It is roughly divided into a sidestream P flowing along the portion 7 on the shelf 11 toward the rear end of the vehicle body. In this way, the air flow in the rear part of the vehicle body can be simply divided because the sidestream Q flows to the rear end of the vehicle body on the shelf 11 and is not affected by the main-stream spoiler 15 in the Y direction at the rear end of the vehicle body. Sufficient velocity component is secured, while
The mainstream F, which is a fast flow flowing from the roof 1 to the rear end of the vehicle body along the rear window portion 3, is decelerated by the mainstream spoiler 15. This is because the flow velocity difference between the main flow F and the side flow P is reduced, and the generation of associated vortices is suppressed.

FIG. 7 shows a streamline around the vehicle body when there are no left and right sidestream spoilers, based on the numerical calculation results.

From the figure, it is expected that in the main flow F, the flow at the central portion is contracted by the triangular vortices E at the left and right ends, and the flow velocity is increased. It is considered that the large turbulence component is largely due to the influence of the triangular vortices E at both ends.
On the other hand, in the sidestream Q, since the generation of the accompanying vortex in the rear pillar portion 7 is suppressed, the flow becomes a uniform and almost laminar flow. From this calculation result, it can be seen that the flow at the rear of the vehicle body is simply divided into the mainstream and the sidestream.

FIG. 8 shows an experimental result of the air spoiler efficiency when a wedge-shaped spoiler of the same shape is installed in the flow of the main flow F and the side flow P as described above.

In the figure, the horizontal axis represents the spoiler attack angle (height), and the vertical axis represents the lift-drag ratio (spoiler efficiency).

As is apparent from FIG. 8, when the spoiler is installed in the main flow F, the lift-drag ratio is small, but the spoiler efficiency is almost linear up to the large angle of attack. On the other hand, when the spoiler is installed in the sidestream Q, the lift-drag ratio is very large, but the spoiler efficiency is saturated at a relatively small angle of attack, so that a large downforce cannot be obtained. The following are possible reasons.

Here, the total pressure loss on the vehicle body surface with respect to the air flow around the vehicle body will be considered.

First, the total pressure P _{t on} the vehicle body surface when the spoiler is installed in the air flow around the vehicle body is the dynamic pressure P _d generated when the air flow, which is the source of the effect, hits the spoiler. , And the static pressure P _{s of the} flow that is pressed vertically against the vehicle body surface that is the source of ground lift (down force).

That is, P _t = P _d + P _s (1)

The dynamic pressure P _d is calculated by the following equation.

P _d = (1/2) ρU ^{* 2} (2) where rho is the air density and U ^* is the flow velocity.

FIG. 9 shows the distribution of total pressure loss in the sidestream portion.

As is clear from the figure, the flow velocity U ^* is smaller than the main flow velocity U _∞ outside the total pressure loss region in the total pressure loss region. Therefore, it can be seen that the dynamic pressure P _d decreases in proportion to the square of the flow velocity U ^* , and that the effectiveness is drastically reduced if the spoiler is installed in the total pressure loss region.

Here, in FIG. 9, the total pressure loss height before installation of the spoiler in the sidestream Q is calculated to be 30 mm, and when the spoiler is installed in the sidestream Q as shown in FIG. 8, the spoiler efficiency rapidly increases. It can be seen that the value is close to the worsening spoiler height (H = 20 mm). Therefore, even if a spoiler having a large height is installed, the flow does not slip on the surface of the object and the flow velocity is low, and the entire spoiler falls within a larger total pressure loss region. A point to be noted here is that the total pressure loss region of the flow naturally changes when the spoiler is installed.

In such a case, the flow around the spoiler changes greatly as compared with the flow before the spoiler is installed, so that the influence of the spoiler wake, which can be a source of drag and ground lift, becomes large. Specifically, in FIG. 8, when the spoiler height of the sidestream spoiler 17 in the sidestream G exceeds 30 mm, the wake greatly differs from the flow before the spoiler is installed and the balance is lost, so that the drag increases. become.

On the other hand, the total pressure Pt in the total pressure loss region is

[Equation 1] Indicated by. Here, ΔP _t is the total pressure loss, and ΔU is the loss of the flow velocity with respect to the main flow velocity U _∞ (vehicle speed wind). In the above equation, the static pressure P _s is invariable, so that the downforce has a substantially constant value regardless of the total pressure loss region.

From the above description, when the spoiler is installed in the sidestream Q, by installing it in a portion which is the total pressure loss region, the same downforce as in the case where it is installed in the mainstream velocity portion can be obtained with the minimum air resistance deterioration margin. Can be secured.

Therefore, in this embodiment, the mainstream spoiler 15 installed in the mainstream F is installed mainly for balancing the flows of the mainstream F and the sidestream Q. Therefore, the initial value of the spoiler height is set regardless of the total pressure loss area.

Further, the sidestream spoiler 17 installed in the sidestream Q is installed for the main purpose of securing the same downforce as the mainstream spoiler 15 with the minimum air resistance deterioration margin. Therefore, the sidestream spoiler 17 is set to a height within the total pressure loss region.

Next, the spoiler control of this embodiment will be described with reference to the flowchart of FIG.

First, in step S1, the vehicle speed sensor 65 and the steering angle sensor 6 input to the digital input detection circuit 55 are input.
7. Based on the outputs from the yaw rate sensor 69 and the lateral G sensor 71, the steering performance of the vehicle is calculated, and the rear wheel downforce value CL _r required to achieve the steering performance is stored in the memory circuit 59. It is calculated by the digital arithmetic circuit 57 on the basis of the specified vehicle specifications, tire data and the like.

Next, at step S2, it is judged if the calculated rear wheel downforce value CL _r is smaller than the threshold value A or not. Here, the threshold value A is the sidestream spoiler 1
7 is the rear wheel downforce value when maximum efficiency is obtained at the angle of attack α.

In step S2, the rear wheel downforce value CL
If it is determined that _r is smaller than the threshold value A, the process proceeds to step S3, and the elevation angle α of the sidestream spoiler 17 at which the downforce CL _r is obtained is set. And step S
At 5, a drive signal is output to the fluid pressure cylinder 51 of the sidestream spoiler 17, and the elevation angle α of the sidestream spoiler 17 is changed to a set value by the expansion and contraction movement of the fluid pressure cylinder 51. At this time, the elevation angle of the mainstream spoiler 15 remains at the initial setting value.

In step S2, the rear wheel downforce value CL
When it is determined that _r is larger than the threshold value A, the process proceeds to step S4, and the elevation angle of the sidestream spoiler 17 is set to the target elevation angle at which maximum efficiency is obtained. And step S5
Then, a drive signal is output to the fluid pressure cylinder 51 of the sidestream spoiler 17, and the angle of attack of the sidestream spoiler 17 is changed and fixed to the target angle of attack by the expansion / contraction drive of the fluid pressure cylinder 51.

[0048] The only offshoot for spoiler 17 In step S6 wheel downforce after shortfall (CL _r -A) is determined, shortage of downforce in step S7 (CL _r
Set the angle of attack of the mainstream spoiler 15 for which (A) is obtained. Then, in step S8, a drive signal is output to the fluid pressure cylinder 38 of the mainstream spoiler 15, and the angle of attack of the mainstream spoiler 15 is changed to a set value by the expansion / contraction drive of the fluid pressure cylinder 38.

In short, in this embodiment, the vehicle speed sensor 6
5, steering angle sensor 67, yaw rate sensor 69 and lateral G
Each output from the sensor 71 is input to the controller 45,
The controller 45 calculates the steering performance of the vehicle based on the above outputs, and obtains the rear wheel downforce amount required to achieve the steering performance from vehicle specifications, tire data, and the like.

When the desired rear wheel downforce amount is within a predetermined value (threshold value), the sidestream spoiler 1 is used.
The angle of attack of No. 7 is changed, and when the rear wheel downforce amount of a predetermined value or more is required, the angle of attack of the mainstream spoiler 15 is also changed. As a result, a suitable downforce with less drag can be obtained.

FIG. 11 shows an experimental result when the above spoiler control is performed.

In the figure, the abscissa axis represents the deterioration of the air resistance C _D when the angle of attack of the spoiler is increased, and the ordinate axis represents the downforce CL _r acting on the vehicle.

According to FIG. 11, when the angle of attack of only the sidestream spoiler installed in the sidestream Q is increased, the downforce C
Although the deterioration amount of C _D is extremely small until L _r is −0.03, C
For downforce with L _r of -0.03 or more, the C _D deterioration margin is extremely large. On the other hand, when the elevation angle of only the mainstream spoiler installed in the mainstream F is increased, the C _D deterioration amount with respect to the downforce CL _r is large compared to the former, but the degree of deterioration of C _D up to a large downforce CL _r changes. I understand that I will not.

Therefore, when the spoiler control according to this embodiment is performed, the elevation angle variable control is performed only by the sidestream spoiler up to the maximum efficiency angle of attack of the sidestream spoiler (CL _r = -0.03 in the figure). , C _D improved about 0.005 with respect to the spoiler control in the main flow F, and CL _r =
-For downforce of 0.03 or more, by performing elevation angle variable control by the mainstream spoiler, the downforce that cannot be supplemented by the sidestream spoiler is 0.005 as compared with the case where only the mainstream spoiler control in the mainstream F is performed. The degree C _D is improved.

Therefore, it became clear that the configuration of the embodiment of the present invention is effective.

The running condition of the vehicle for determining the spoiler control amount (rear wheel downforce amount) may be as shown in the following (1) to (4). That is, (1) Downforce is determined so that the relationship between the vehicle stability factor and the yaw resonance frequency changes linearly with respect to the vehicle.

In this case, the vehicle states to be detected are the front and rear wheel loads and the vehicle speed, and the control targets are the mainstream spoiler and the sidestream spoiler.

(2) The downforce is determined by detecting the crosswind acting on the vehicle body.

In this case, the vehicle states to be detected are the lateral wind velocity, the front and rear wheel loads, and the vehicle speed, and the control targets are the mainstream spoiler and the windward sidestream spoiler.

(3) The down force is determined by detecting the roll moment acting on the vehicle body.

In this case, the vehicle states to be detected are the roll angle, the front and rear wheel loads, and the vehicle speed, and the control targets are the mainstream spoiler and the sidestream spoiler that generates the reverse roll moment.

(4) The downforce is determined by detecting the friction coefficient of the road surface.

In this case, the detected vehicle state quantities are the friction coefficient of the road surface, the front and rear wheel loads, and the vehicle speed, and the control targets are the mainstream spoiler and the sidestream spoiler.

[0064]

As is apparent from the above description, according to the invention of claim 1, the mainstream spoiler is acted on the mainstream of the rear part of the vehicle body and the sidestream spoiler is acted on the sidestream. It is possible to easily achieve both reduction and securing downforce.

According to the second aspect of the present invention, when the desired downforce is less than the predetermined value, only the sidestream spoiler is operated, and when the downforce exceeding the predetermined value is required, the mainstream spoiler is used together. The desired downforce can be achieved with less air resistance.

According to the third aspect of the present invention, by substantially controlling the mainstream spoiler and the left and right sidestream spoilers according to the running state of the vehicle, a downforce according to the running state can be positively obtained. .

According to the invention of claim 4, the spoiler height of the sidestream spoiler can be effectively and rationally set, and the reduction of air resistance and the increase of downforce can be more effectively obtained. .

[Brief description of drawings]

FIG. 1 is a perspective view according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a mainstream spoiler of one embodiment.

FIG. 3 is a sectional view showing a mainstream spoiler of one embodiment.

FIG. 4 is a cross-sectional view showing a sidestream spoiler of one embodiment.

FIG. 5 is a block diagram of a controller according to an embodiment.

FIG. 6 is a schematic diagram showing the flow of air in the rear part of the vehicle body.

FIG. 7 is an explanatory diagram of streamlines around the vehicle body.

FIG. 8 is an explanatory diagram of effects of the mainstream spoiler and the sidestream spoiler according to the embodiment.

FIG. 9 is a total pressure loss distribution map in a sidestream portion of a vehicle body.

FIG. 10 is a control flowchart of one embodiment.

FIG. 11 is an explanatory diagram showing an experimental result of one example.

FIG. 12 is a perspective view showing a conventional example.

13 is a sectional view taken along the line XIII-XIII in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 roof 7 rear pillar part 9 throttle line 11 shelf part 15 mainstream spoiler 17 sidestream spoiler 45 controller (control means) 65 vehicle speed sensor (running state detection means) 67 steering angle sensor (running state detection means) 69 yaw rate sensor (running) State detection means) 71 Lateral G sensor (running state detection means)

Claims (4)

[Claims] 1. The height of the rear part of the vehicle body is formed so as to gradually decrease from the roof to the rear end of the vehicle body, and the lateral width of the outer surface on the upper side of the rear part of the vehicle body is gradually narrowed toward a rear end of the vehicle body along a predetermined diaphragm line. In the vehicle body structure, the main body spoiler is formed between the intersections of the left and right throttle lines and the vehicle body rear end at the vehicle body rear end. An air spoiler device, characterized in that a sidestream spoiler is provided at the rear ends of the left and right shelf portions. 2. The air spoiler device according to claim 1, wherein the mainstream spoiler and the sidestream spoiler are set to have different aerodynamic characteristics, and only the sidestream spoiler is normally supported in an operating state, and downforce is applied. An air spoiler device comprising: a supporting means for variably supporting the mainstream spoiler from a non-operating state to an operating state when necessary, and a control means for controlling the supporting means. 3. The air spoiler device according to claim 1, further comprising a traveling state detecting means for variably supporting the mainstream spoiler and the left and right sidestream spoilers and detecting a traveling state of the vehicle. An air spoiler device comprising a control means for controlling the mainstream spoiler and the left and right sidestream spoilers based on an output signal from the detection means. 4. The air spoiler device according to claim 1, 2 or 3, wherein the spoiler height of the sidestream spoiler is set to a height within a total pressure loss region at a rear end of the shelf-shaped portion before installation of the spoiler. An air spoiler device characterized in that