JPH0367784A - Air spoiler for vehicle - Google Patents

Abstract

PURPOSE:To reduce a yawing moment and the air resistance respectively by providing a number of ventilation holes on an air spoiler installed at the front part of a vehicle and at the same time, providing at respective ventilation holes follower means which respectively conduct following rotation in the direction of a wind the vehicle receives. CONSTITUTION:A horizontal wind spoiler 3 of a plate shape is provided all over the lower part of the front of a vehicle 1. Also, a number of ventilation holes 5 are provided thereat. In addition, at the inside of each ventilation hole 5, a rotary pipe portion 7 which is a follower means and rotates within a predetermined angle range, is rotatably supported. When the vehicle 1 receives a lateral wind while traveling, it receives the synthetic wind due to yaw angle at the same time, and a yawing moment around the center of gravity is generated. And in case the yaw angle is within a set value, the rotary pipe portion 7 is rotated by the synthetic wind and directed in the direction of the synthetic wind, and the air resistance is reduced. In case the yaw angle is more than a set value, the quantity of wind passing through the rotary pipe portion 7 is reduced, and the yawing moment is thereby reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air spoiler provided at the front of a vehicle, and more particularly to an air spoiler that reduces yawing moment acting on the vehicle and improves running stability.

[Conventional technology]

BACKGROUND ART Some conventional air spoilers for vehicles are designed to reduce yawing moment when driving in a crosswind, thereby contributing to improving the running stability of a vehicle.

[The problem that the invention aims to solve]

However, while this air spoiler can reduce the yawing moment when traveling in a crosswind, it tends to increase air resistance.

For this reason, especially when driving at high speeds, installing this air spoiler may increase air resistance and reduce fuel efficiency stability.

The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicle air spoiler that can reduce yawing moment and suppress an increase in air resistance.

[Means to solve the problem]

In order to achieve the above object, the present invention Q provides a vehicle air spoiler provided at the front of a vehicle, including a ventilation hole that passes through the air spoiler, and a ventilation hole that is rotatable within a predetermined angle. and a following means that is supported by the vehicle and follows the direction of the wind that the vehicle receives.

[Effect]

In the present invention configured as described above, when the angle between the direction of the wind hitting the air spoiler and the direction of travel of the vehicle is smaller than a predetermined value, the following means rotatably supported in the ventilation hole allows the wind to pass through. to reduce air resistance (air resistance coefficient CD).

If the angle between the direction of the wind hitting the spoiler and the direction of travel of the vehicle is greater than the predetermined value, the following means can no longer rotate by more than the predetermined angle, so the amount of wind passing through the following means decreases, causing the air spoiler to It is possible to reduce the yawing moment to the same extent as when there is no ventilation hole.

〔Example〕

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

As shown in the figure, a plate-shaped crosswind spoiler 3 made of polyurethane resin or fiber-reinforced plastic is provided on the entire front lower part of the vehicle.
is provided with four ventilation holes 5, and furthermore, these ventilation holes 5
A follow-up means (rotating cylinder part) 7 which rotates within a predetermined angle is rotatably supported inside. As can be seen from Fig. 2, the thickness of the crosswind spoiler 3 is t-20mm, the thickness of the ventilation hole 5 portion is t' = 100m, the height H is 150m, and the size of the ventilation hole 5 is the width w. =50mm, height h=1
00mm.

The following means 7 has a structure that rotates due to wind pressure, and its detailed structure is shown in FIGS. 3 and 4. Figure 3 (b) is a sectional view taken along line A-A in Figure 3 (a), and Figure 3 (C) is a cross-sectional view of the third
FIG. 4 is a sectional view taken along the line BB in FIG. The crosswind spoiler 3 is provided with an upper shaft 9 and a lower shaft 11 at a position forward of the aerodynamic center of the rotary tube portion 7, and these serve as the central axis of the following means 7 and rotatably support the following means 7. do. and,
Since the stopper 13 protruding from the spoiler 3 fits into the stopper hole 15, the following means 7 can only move within the angle of the hole.
cannot be rotated. This stopper hole 1
5 is an adjustment so that the direction in which the hole of the follower means 7 is placed can be rotated by ±10° with respect to the traveling direction of the vehicle.

Further, when the following means 7 is not subjected to wind pressure, the spiral coil spring 17 is provided so that the direction in which the hole of the following means 7 is placed is held parallel to the traveling direction of the vehicle. By inserting and fixing one end of this spring 17 into the small hole 21 of the main body of the spoiler 3 and the other end into the small hole 19 of the following means 7, the following means 7 is always kept in the hole of the following means 7 when there is no wind. The direction is kept parallel to the direction of travel of the vehicle.

Next, the operation of this embodiment configured as above will be explained. As schematically shown in FIG. 5, vehicle 1 is at vehicle speed ■. When vehicle 1 receives a crosswind V while driving at yaw angle ψ
will receive the synthetic wind V.

The synthetic wind V causes a yawing moment about the center of gravity of the vehicle 1. This yawing moment has the function of disturbing the straight-line motion of the vehicle and impairing running stability when driving at high speeds. As shown in FIG. 6, one of the causes of this yawing moment is the generation of a negative pressure area 23 in front of the side surface. This negative pressure area 23 is very large in a one-box car due to its shape.

In this embodiment, if the yaw angle ψ is within ±10°, the rotating cylinder part 7 overcomes the force of the spring 17 due to the wind pressure of the synthetic wind ■, rotates ψ to face the direction of the synthetic wind ■, and the air resistance decrease.

When the crosswind ■3 increases and the yaw angle ψ becomes larger than ±10°, the following means 7 can only rotate within ±10", so the amount of wind passing through the following means 7 decreases, reducing the yawing moment. .

Next, experimental results in this example will be explained in comparison with the conventional technology. FIG. 6 shows the distribution of causes of yawing moment when no air spoiler is provided.

FIG. 7 shows the distribution of negative pressure when a conventional air boiler is provided.

The numbers in FIGS. 6 and 7 represent the value of the pressure coefficient C force. The pressure coefficient C7 is CP-P/('A・ρ・v), where P is the surface pressure of the vehicle, ρ is the air density, and ■ is the composite wind speed. Comparing Fig. 7, it can be seen that the negative pressure area in front of the side of the vehicle is reduced by providing an air spoiler.However, although providing an air spoiler reduces the yawing moment, it also reduces air resistance. This is shown in Fig. 8. In Fig. 8, the solid line is the case with the air spoiler, and the broken line is the case without the air spoiler, and the air resistance coefficient C11 is Cゎ=F. /(y2・ρ・U2・S), and the yawing moment coefficient C''lN is C
It is expressed as YM-M/ (% ・p ・U"-3-L), where F is drag, U is mainstream speed, ρ is density, S is frontal projected area, M is yawing moment, and L is wheel As described above, when a conventional air spoiler is used, C9 increases by more than 10%, and this increase in Go causes deterioration in fuel efficiency.

In general, since the yawing moment coefficient Cv and the air resistance coefficient CD have contradictory properties, it is impossible to reduce both Cvn and Cn at all yaw angles. Therefore, when the crosswind is strong (yaw angle ψ is large), emphasis is placed on crosswind stability and the yawing moment coefficient Gv14 is reduced;
If the coefficient is small, it is necessary to make a case-by-case decision, such as placing emphasis on fuel efficiency and lowering the air resistance coefficient Co. As a guideline for the boundary of Gv, Co control by this yaw angle ψ, W o
1 fHeinrich Hucho[rAero
Dynasics of Road Vehicle (
According to the 24th line of P218 to P219), the yaw angle is ±10°. Therefore, in this example,
When the yaw angle ψ is less than ±10'', priority is given to suppressing the air resistance coefficient CD, and when the yaw angle ψ is greater than ±10°, priority is given to reducing the yawing moment coefficient G.

The cause of the increase in Co in the plate-shaped spoiler is the negative pressure area generated on the rear surface of the spoiler. Therefore, reducing the negative pressure area on the rear surface of the spoiler by providing ventilation holes as shown in FIG. 10 is effective in suppressing the increase in CD. However, as the ventilation holes become larger, the original function of the spoiler (Cyw low tli) becomes smaller.

Therefore, there is a need for a means to enlarge the ventilation holes (lower the C force) without increasing the yawing moment coefficient CVH as much as possible, and as shown in FIG.
It is only necessary to make the thickness t' of t' = 100s, which is thicker than t.
Differences in air volume passing through ventilation holes due to differences in plate thickness (wind speed distribution)
are shown in FIGS. 9(a) to 9(d). As shown in Figures 9(a) and (d), when the yaw angle is 0°, both exhibit similar wind speed distributions, but when the yaw angle is 30'', Figure 9 shows the wind speed distribution when the plate thickness is thin. Compared to figure (b), the plate thickness t
'-100mm, as shown in Figure 9 (C), the wind speed is greatly reduced and it is similar to a plate-shaped spoiler without ventilation holes, which can reduce CVM.
o.

CYN is shown in Figure 11, CYM is 4 at a yaw angle of 30”.
0% or more Co is suppressed to almost the same level as in the case without a spoiler at a yaw angle of 0°.

Here, as a means to make the ventilation hole larger without increasing the yawing moment coefficient Cv,4 as much as possible, the thickness t' of the air spoiler ventilation hole 5 is changed to t' as shown in FIG.
= 100 mm, which is thicker than t, allows the wind to flow without resistance when the yaw angle ψ is Oo, and as the yaw angle ψ increases, the wind flows more easily. However, as a remaining problem, the air resistance coefficient Co still increases in the range of yaw angle ψ=5 to 10 degrees. We want to suppress the increase in the air resistance coefficient CD as much as possible up to the yaw angle ψ-10°, so we set the angle of this ventilation hole to ±lO°.
It was made variable within the range of. By making the yaw angle ψ variable
The wind speed passing through the ventilation hole increases to 0.000000000000000000000000000000000000000000000000000000000000000000000000.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00; Figure 11 shows the relationship between the yaw angle φ, the air resistance coefficient CD, and the yawing moment coefficient C7,4 when the following means is attached to the ventilation hole. When an air spoiler with ventilation holes is used, the dashed-dotted line shows the case when a spoiler without ventilation holes is used, and the solid line shows the case when the air spoiler according to this embodiment is used. 11th
As can be seen from the figure, when the yaw angle ψ is in the range of 0° to ±10′, the increase in the air resistance coefficient C is suppressed to the same level as in the case without the spoiler. Furthermore, it can be seen that at yaw angles of ±10" or more, there is an effect of reducing the yawing moment coefficient C1l equivalent to that of a spoiler without ventilation holes. Also, FIGS. 9(e) and (f) show that the spoiler according to this example Shows the spoiler wind speed distribution.

In this embodiment, a rotary cylinder was used as the following means, but instead of this, rotatably supported fins were used as the following means.
It may be possible to follow the direction of the wind within a range of 10".

Also, in all embodiments of the present invention, there is no wind-blocking object (such as a radiator, etc.) immediately after the air spoiler.

Next, the second embodiment of the present invention is shown in FIGS. 12(a) and 12(a).
In the present embodiment shown in Figure 3), the crosswind spoiler 3 of the first embodiment described above is deployed and retracted depending on the vehicle speed.

Since the crosswind spoiler is most effective when driving at high speeds, it receives a signal from a known vehicle speed sensor and is controlled so that it is deployed when driving at high speeds and retracted when driving at medium or low speeds. The method of operation may be any known method. Since there is a risk of damaging the spoiler when driving on rough roads, it is effective to make it open and close. The operation will be briefly explained below using FIGS. 12(a) and 12(b). A worm and a worm wheel are contained in the gear box 50, and reduce the rotation speed of the motor to an appropriate rotation speed (about 3 rpm). Note that this gear box 50 is fixed to a stopper 52. The driving force is transmitted to the shaft 54, and since this shaft 54 is fixed to the air spoiler 3, the shaft 54 is rotated by forward and reverse rotation of the motor, and the air spoiler is expanded and retracted.

Here, the stopper 52 acts as a stopper that determines the stop position of the air spoiler 3.
2, the motor can be switched off by obtaining a signal from a potentiometer (not shown) or by detecting the flow tvL due to an overload applied to the motor, and then turning off the motor. In this embodiment, when the air spoiler is deployed, it is as shown in FIG. 12 (B), and when it is stored, only the stopper 52 remains at the bottom of the bumper, and the air spoiler 3 is hidden at the bottom of the vehicle.

As a third embodiment, considering cost etc., only the ventilation holes may be provided without providing the following means.The ventilation holes may be arranged parallel to the traveling direction of the vehicle, and the plate thickness By increasing the thickness, the amount of ventilation can be reduced when the yaw angle is large, and the amount of ventilation can be increased when the yaw angle is 0°.

As a fourth embodiment, in the first embodiment, the following means is rotated by wind pressure, but a wind sensor detects the wind direction, and an actuator such as a motor is used to adjust the direction of the following means from 0 to ±±. It may be changed within a range of 10 degrees.

〔Effect of the invention〕

As explained above, according to the present invention, priority is given to reducing air resistance and reducing yawing moment at a predetermined angle. This has the excellent effect of suppressing the increase in

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example in which the first embodiment of the present invention is applied to a one-box car, Fig. 2 is a perspective view showing the main part of the above embodiment, and Fig. 3 (a) is a perspective view showing the above embodiment. Figure, Figure 3 (6
) is a cross-sectional view taken along line A-A in Figure 3(a), and Figure 3(C) is a cross-sectional view of the third
Figure 4 is a perspective view of the main parts showing the assembled state of the above embodiment, Figure 5 is a schematic diagram for explaining the yaw angle in the above embodiment, and Figure 6 Figure 7 shows the negative pressure distribution without an air spoiler, Figure 7 shows the negative pressure distribution with a conventional air spoiler, and Figure 8 shows the yaw distribution without an air spoiler and with a conventional air spoiler. A graph showing the relationship between angle and CD + CVM,
Figures 9 (a) to (f) are diagrams comparing the wind speed distribution of various spoilers when the yaw angle is 0° and 30'', and Figure 10 is the pressure distribution on the rear surface of the air spoiler with and without ventilation holes. Fig. 11 is a comparison diagram of the case where there is no air spoiler (dashed line) and the case where an air spoiler without ventilation holes is used (
Yaw angle and C1°cv when using an air spoiler with fixed ventilation holes (double-chain 1a), and when using the air spoiler of the above embodiment with movable ventilation holes (solid line), FIG. 12(a) is a perspective view showing a second embodiment of the present invention, and FIG. 12(b) is a sectional view taken along line AA in FIG. 12(a). 3... Air spoiler, 5... Ventilation hole, 7... Following means.

Claims (1)

[Claims] (1) A vehicle air spoiler installed at the front of a vehicle includes a ventilation hole that passes through the air spoiler, and a rotatable rotatable rotatable portion within a predetermined angle supported by the ventilation hole to follow the direction of wind received by the vehicle. A vehicular air spoiler comprising: a follow-up means.