JPH06227436A - Air guide structure for vehicle wheel house - Google Patents

Abstract

PURPOSE:To provide an air guide structure which can drastically improve the overall aerodynamic characteristic of a vehicle by lowering the pressure by efficiently disaharging the air in the wheel house of the vehicle outside. CONSTITUTION:The first opened port part 7 for introducing air is formed in a wheel house 3 above in the vehicle advance direction which is divided by a vertical line L1 in the perpendicular direction passing through the rotary shaft 4a of a wheel 4 and a straight line L2 passing through the front lower edge 6 of the wheel house 3, and the second opened port part 8 for disharging air is formed on the undersurface F1 of the vehicle and the first and the second opened port parts 7 and 8 are allowed to communicate through an air passage 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air guide structure for a vehicle wheel house capable of reducing the pressure in the wheel house and improving the aerodynamic characteristics of the vehicle.

[0002]

2. Description of the Related Art In a wheel house of a vehicle, wheels rotate at a high speed, so that the air pressure inside the wheel house changes.
It is known to adversely affect the aerodynamic characteristics of the vehicle.
Therefore, as is known from Japanese Utility Model Laid-Open No. 3-60171, an air vent hole is provided on the rear surface of the wheel house, and the air inside the wheel house is vented to the rear of the vehicle body from this hole to improve the aerodynamic characteristics of the vehicle. There is an air guide structure that tries to achieve

[0003]

However, in such a conventional air guide structure, in actuality, the air in the wheel house does not escape to the rear of the vehicle to the extent that a sufficient improvement in the aerodynamic characteristics of the vehicle can be expected.

The present invention has been made by paying attention to such a conventional technique. The air in the wheel house of the vehicle is efficiently exhausted to the outside to reduce the pressure, thereby improving the overall aerodynamic characteristics of the vehicle. (EN) Provided is an air guide structure for a vehicle wheel house, which can significantly improve

[0005]

An air guide structure for a vehicle wheelhouse according to the present invention is divided into a vertical line passing through a rotation axis of a wheel and a straight line which is orthogonal to the vertical line and passes through a front lower end of the wheelhouse. A first opening for introducing air and a second opening for discharging air are provided on the lower surface of the vehicle in the wheel house above the traveling direction of the vehicle, and the first opening and the second opening are provided. And are communicated with each other through an air passage.

[0006]

According to the present invention, since the air can be efficiently exhausted to the outside from the region where the atmospheric pressure is the highest in the wheel house, the overall aerodynamic characteristics of the vehicle relating to the air resistance, the lift characteristics, etc. can be greatly improved. Can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the figure, F indicates the front and B indicates the rear.

1 to 5 are views showing a first embodiment of the present invention. First, before describing a specific structural example of the present embodiment, a flow of air around a wheel house of a vehicle will be described with reference to FIGS. 4 and 5. 1 is a front part of the vehicle, 2 is a bumper part, 3 is a wheel house, F ₁ is a vehicle lower surface in front of the wheel house 3, F ₂ is a vehicle lower surface in a rear position, 4 is a wheel, and 4 a is a rotating shaft. , Α is wheel 4
And the G indicates the road surface.

A flow A of air from the front of the vehicle is a flow A ₁ upward of the vehicle with a stagnation point T which hits the bumper portion 2 as a boundary.
And the flow A ₂ downward to the vehicle. Furthermore, the flow A ₂ of the vehicle downward and detached from the vehicle lower surface F ₁ at the vehicle front lower end 5, a flow A ₃ toward the wheel 4 while generating a vortex R _1, the wheel house 3 and the wheel 4 with the vortex R ₁ It splits into a flow A ₄ that enters between and.

On the other hand, on the wheel 4, a flow A ₅ induced by the rotation of the wheel 4 is generated in the same rotation direction α as the wheel 4. Then, the flow A ₄ and the flow A ₅ collide with each other near the point P on the front side of the wheel 4 and above the vehicle. Therefore, the pressure at the point P becomes relatively high in the wheel house 3, and it is effective to exhaust the air in the wheel house 3 from around this point. This point P is
A vertical line L ₁ passing through the rotation axis 4a of the wheel 4 and a region H above the vehicle traveling direction which is orthogonal to the vertical line L ₁ and is divided by a straight line L ₂ which is substantially parallel to the road surface G passing through the front lower end 6 of the wheel house 3.
The position of the point P in the region H is determined by the shape of the wheel house 3, the size of the wheels 4, and the like.

Further, the air flows A ₄ and A ₅ colliding near the point P flow out to the surface side of the wheel 4 where the pressure outside the vehicle is low and generate a vortex R ₂ . This vortex R
_As shown in FIG. 5, ₂ disturbs the flow A ₆ from the front of the vehicle and not only increases the air resistance of the vehicle, but also causes a splash (mud splash) around the door. Further, the rise in pressure in the wheel house 3 increases the lift of the vehicle, so that it is not possible to improve the overall aerodynamic performance.

Next, a specific structural example of the present embodiment constructed by confirming the flow of air around the wheel house 3 as described above will be described with reference to FIGS. That is,
In the wheel house 3 according to the first embodiment, a first opening 7 is formed near a point P where the air flow A ₄ and the air flow A ₅ collide with each other, and on the front side of the front lower end 6 of the wheel house 3. A second opening 8 is formed on the adjacent vehicle lower surface F _1, and the first opening 7 and the second opening 8 form an air passage 9
Are in communication with each other. Therefore, the flows A ₄ and A ₅ colliding near the point P become a flow A ₇ after being introduced from the first opening portion 7 through the air passage 9 and from the second opening portion 8 of the vehicle lower surface F ₁ . Exhausted. The height h ₁ of the front lower end 6 of the wheel house 3 as the “rear end” of the second opening 8 is set to be equal to or higher than the height h ₂ of the front end 10 of the second opening 8. (H ₁ ≧
h ₂ ). As a result, the front lower end 6 of the wheel house 3, which is the “rear end” of the second opening 8, does not receive the traveling wind, and the air flow A ₇ is reliably discharged from the second opening 8. Becomes

As described above, the flows A ₄ and A ₅ colliding near the point P are introduced into the air passage 9 from the first opening 7 and flow from the second opening 8 to the vehicle lower surface F ₁ A ₇ As a result, the vortex R ₂ flowing out to the surface side of the wheel 4 and causing the air resistance of the vehicle is greatly reduced, and as shown in FIG. 3, the flow A ₆ from the front of the vehicle is almost discharged to the vehicle body. Since it follows along, air resistance of the vehicle can be reduced. Further, the flow A ₃ entering the vehicle lower surface F ₁ from the vehicle front is
The flow A ₇ exhausted from the second opening 8 is directed to the road surface G side, and this relatively fast flow A ₃ is less likely to hit the wheels 4 directly, which also contributes to the reduction of the air resistance. Further, since the vortex R ₂ becomes smaller, the splash around the door can be reduced. Moreover, point P
Since the flows A ₄ and A ₅ colliding with each other in the vicinity can be introduced from the first opening 7 and exhausted from the second opening 8, the wheel house 3
At the same time, the internal pressure is reduced and the lift of the vehicle is reduced. As a result, the overall aerodynamic characteristics of the vehicle are improved.

6 to 8 are views showing a second embodiment of the present invention. In this embodiment, the vehicle lower surface F ₁ in front of the second opening 8 has a width substantially corresponding to the second opening 8,
A flap member 11 having a height h ₃ is provided. Flow A ₂ having entered from the vehicle front to the vehicle underside F ₁ is for stripping in the flap member 11 from the vehicle lower surface F _1, the flap member 11, until reattachment point which is the end point of the stripping has a low pressure Become. Therefore, if the second opening 8 is arranged within the range from the flap member 11 to the redeposition point, the air in the wheel house 3 can be exhausted more efficiently.

The relationship between the distance X _R from the flap member 11 to the reattachment point, the height h ₃ of the flap member 11 and the Reynolds number Re is as shown in FIG. 8 (Source: Ichiro Tani)
Fluid dynamics laminar flow, Maruzen Co., Ltd.). The Reynolds number Re can be expressed by the following equation.

Re = (2HV) / ν (1) where H is the height (h ₃ ) of the flap member 11, V is the flow velocity of the approaching air (approximately vehicle speed), and ν is air. Is a kinematic viscosity coefficient of 0.154 × 10 ⁴ m ² / s.

According to FIG. 8, Re is approximately 600 (area in the figure
Above (center of III), the reattachment point becomes almost constant. When the height h ₃ of the flap member 11 is about 50 mm, R
When the flow velocity at which e becomes 600 or more is calculated, it becomes about 0.1 m / s, and it can be said that Re is always 600 or more during normal traveling of the vehicle. Therefore, the reattachment point of the flow A ₂ separated by the flap member 11 having the height of h ₃ is as shown in FIG.
It can be seen that it is within 10 × h ₃ . That is, in FIG. 8, in the range where Re is 600 or more, the value of X _R / H is 10 or less for all data such as plots ◯ and Δ. Therefore, the distance D from the flap member 11 shown in FIG. 6 to the front lower end 6 of the wheel house 3 which is the “rear end” of the second opening 8 is within 10 times the height h ₃ of the flap member 11. In this case (D ≦ 10h ₃ ), the second opening 8 always exists in the range where the pressure is low. Therefore, the exhaust effect of the air in the wheel house 3 is further improved. Furthermore,
Due to the flow A ₇ exhausted from the flap member 11 and the second opening 8, the fast flow A ₃ from the front of the vehicle does not hit the wheels 4 further than in the first embodiment, and the air resistance is further reduced. The overall aerodynamic performance is further improved.
In this embodiment, the front lower end 6 of the wheel house 3 has the same height as the vehicle lower surface F ₁ . Other configurations and operational effects are similar to those of the previous embodiment.

FIG. 9 is a diagram showing a third embodiment of the present invention. In this embodiment, the second opening 12 is provided on the vehicle body lower surface F ₂ behind the wheel house 3.
The second opening 12 is provided at the rear lower end 13 of the wheel house 3.
The rear lower end 1
The flap member 14 is disposed between the third opening 3 and the second opening 12. Therefore, the flow A introduced from the first opening 7
₇ passes through the air passage 15 and is discharged from the second opening 12. This embodiment, since hits rapid flow A ₃ to the wheel 4, as compared to the above embodiments, but is slightly disadvantageous with respect to aerodynamic drag reduction, the vehicle body lower surface F ₁ of the front wheel house 3 'second opening " It is effective when it cannot be installed. Other configurations and operational effects are similar to those of the previous embodiment.

FIG. 10 is a diagram showing a fourth embodiment of the present invention. In this embodiment, the second opening 8 shown in the second embodiment is used.
In place of the “flap member”, a strike-shaped (wedge-shaped) aerodynamic member 16 is provided on the vehicle lower surface F ₁ in front of the above. The aerodynamic member 16 has a height h ₄ , separates the flow A ₂ entering the vehicle lower surface F ₁ from the front of the vehicle, and, like the above-mentioned “flap member”, the flow A from the second opening 8 is formed.
_It works to promote the discharge of ₇ . Moreover, since the aerodynamic member 16 has a strike shape advantageous in terms of air resistance, the flow A entering the vehicle lower surface F ₁ from the front of the vehicle A
The resistance of ₂ is not so great, and the overall aerodynamic performance of the vehicle can be further improved. In this embodiment, the aerodynamic member 16 having a strike shape is used as a component for the vehicle lower surface F.
_Although the example provided in FIG. ₁ is shown, if the shape of the vehicle lower surface F ₁ itself is a strike shape, the number of parts can be reduced accordingly. Other configurations and operational effects are similar to those of the previous embodiment.

11 and 12 show the fifth embodiment of the present invention. In this embodiment, the wheel house 3 is provided with a passage forming member 17 having a degree of curvature corresponding to the wheel house 3 and a hat-shaped cross section. Therefore, the air passage 18 is formed between the wheel house 3 and the passage forming member 17, and the first opening 19 and the second opening 20 are formed at the upper and lower ends thereof. The first opening 19 is located at the point P in the region H as in the previous embodiment,
The second opening 20 is located slightly above the front lower end 6 of the wheel house 3. That is, since the lower end 21 of the second opening 20 is slightly above the front lower end 6 of the wheel house 3, the flow A ₇ is reliably discharged from the second opening 20. In this example, there is no need to modify the vehicle body,
There is an advantage that you do not have to worry about the layout inside the vehicle body near the wheel house 3. In addition, the wheel house 3 such as trucks
It is even more advantageous if it is applied to a mudguard used in. Other configurations and operational effects are similar to those of the previous embodiment.

13 and 14 are views showing a sixth embodiment of the present invention. In this embodiment, the first opening 7 is provided at the same position as in the first embodiment, and the vehicle center line S and the wheels 4 are provided.
The second opening 22 is provided on the vehicle lower surface F ₁ in the region between the two, and the first opening 7 and the second opening 22 are communicated with each other by the air passage 23. In the case of this embodiment, FIG.
As shown by the velocity distribution of the air flowing under the floor of the vehicle,
Due to the slow flow A ₇ discharged from the second opening 22, the flow A of air flowing from the front of the vehicle to the center of the lower surface F ₁ of the vehicle.
₈ is contracted to become a high-speed flow A ₉ . The fast flow A ₉ due to this contraction reduces the lift of the vehicle, and is particularly effective in improving the steering performance at high speeds. Therefore, this embodiment is effective for a mid-ship vehicle or a rear engine vehicle that does not require an engine or a transmission that provides air resistance at the front portion.

[0022]

The air guide structure of the vehicle wheel house according to the present invention has the contents as described above, and therefore, by efficiently exhausting air to the outside from the region where the atmospheric pressure is the highest in the wheel house. The overall aerodynamic characteristics of the vehicle regarding air resistance, lift characteristics, etc. can be significantly improved.

Further, since the area where the atmospheric pressure is high in the wheel house is reduced, the splash phenomenon which is seen in the conventional vehicle is suppressed. Therefore, there is also an effect that dirt on the side surface of the vehicle is unlikely to adhere.

[Brief description of drawings]

FIG. 1 is a side view of a vehicle showing an air guide structure of a vehicle wheel house according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the structure inside the wheel house of the first embodiment.

FIG. 3 is a plan view showing the vehicle of the first embodiment.

FIG. 4 is a side view of a vehicle corresponding to FIG. 1 for explaining the first embodiment of the present invention.

FIG. 5 is a plan view of a vehicle corresponding to FIG. 3 for explaining the first embodiment of the present invention.

FIG. 6 is a side view of a vehicle corresponding to FIG. 1 showing an air guide structure for a vehicle wheel house according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a lower surface of a vehicle showing a second embodiment.

FIG. 8 is a graph showing the relationship between the height of the flap member, the reattachment point, and the Reynolds number.

FIG. 9 is a side view of a vehicle corresponding to FIG. 1 showing an air guide structure for a vehicle wheel house according to a third embodiment of the present invention.

FIG. 10 is a side view of a vehicle corresponding to FIG. 1 showing an air guide structure of a vehicle wheel house according to a fourth embodiment of the invention.

FIG. 11 is a side view of a vehicle corresponding to FIG. 1 showing an air guide structure for a vehicle wheel house according to a fifth embodiment of the present invention.

FIG. 12 is a perspective view showing the structure inside the wheel house of the fifth embodiment.

FIG. 13 is a perspective view showing a lower surface of a vehicle of an air guide structure for a vehicle wheel house according to a sixth embodiment of the present invention.

FIG. 14 is a diagram showing an air flow velocity distribution of an air guide structure for a vehicle wheel house according to a sixth embodiment.

[Explanation of symbols]

3 Wheelhouse 4 Wheel 4a Rotating shaft 7,19 First opening 6,13 Front lower end 8,12,20,22 Second opening 9,15,18,23 Air passage 11,14 Flap member 17 Passage forming member 16 Stroke-shaped aerodynamic member G Road surface L ₁ perpendicular line L ₂ Straight line orthogonal to perpendicular line H area S Vehicle center line F ₁ , F ₂ Vehicle bottom surface A _{1 to} A ₉ Air flow

Claims (7)

[Claims] 1. A vertical line passing through a rotation axis of a wheel in a vertical direction,
In the wheel house above the traveling direction of the vehicle, which is orthogonal to the perpendicular and is separated by a straight line passing through the lower front of the wheel house,
A first opening for introducing air and a second opening for discharging air are provided on the lower surface of the vehicle, and the first opening and the second opening are in communication with each other through an air passage. Air guide structure for vehicle wheel house. 2. The air guide structure for a vehicle wheel house according to claim 1, wherein the second opening is provided on a lower surface of the vehicle body in front of the wheel house. 3. The air guide structure for a vehicle wheel house according to claim 1, wherein the second opening is provided on a lower surface of the vehicle body behind the wheel house. 4. The air guide structure for a vehicle wheel house according to claim 1, wherein the second opening is provided on the lower surface of the vehicle between the vehicle center line and the wheel. 5. A flap member having a constant height downwardly of the vehicle is arranged at a position within 10 times the height of the flap member from the rear end of the second opening portion toward the front.
4. The vehicle wheel house air guide structure described in 4. 6. The air guide structure for a vehicle wheel house according to claim 1, wherein a vehicle lower surface in front of the second opening portion of the vehicle has a strike shape. 7. A passage forming member for forming an air passage is provided in the wheel house, and an air introducing first opening on the upper side of the air passage is a straight line perpendicular to a road surface passing through a rotation axis of a wheel.
To be located near the front area above the vehicle, which is divided by a straight line parallel to the road surface that passes through the lower front of the wheelhouse, and the lower second air discharge opening is located near the lower front edge of the wheelhouse. An air guide structure for a vehicle wheel house.