JP5186812B2 - Automotive front structure - Google Patents

Description

  The present invention relates to a front structure of an automobile.

  2. Description of the Related Art Conventionally, techniques for improving the running characteristics of an automobile without impairing the appearance of the automobile have been proposed. For example, Patent Document 1 discloses a front structure of an automobile in which saddle-shaped projecting surfaces are provided at corners of a front bumper fascia. In the front structure of the automobile, when the automobile is running, a negative surface pressure is generated in the vicinity of the surface of the saddle-shaped protruding surface, thereby generating a force for pulling the automobile forward, reducing the air resistance of the automobile, and The saddle-shaped projecting surface does not cause the front bumper fascia to bulge forward as a whole, so that the appearance of the front part of the automobile is not impaired.

Further, as shown in FIGS. 10, 11, and 12, there is an automobile in which a skirt portion 100 that bulges toward the front of the vehicle body is provided at the corner portion 12 of the front bumper fascia 4. The skirt portion 100 is formed at the lower portion of the corner portion 12 and has a shape that rises toward the rear of the vehicle body. By providing the skirt portion 100, downforce is given to the automobile, and it is possible to avoid the traveling wind flowing along the surface of the corner portion 12 from colliding with the front wheel. Moreover, since the upper part 21 of the corner part 12 having a large visual influence does not exhibit an angular shape because the skirt part 100 is not formed, the appearance of the front part of the automobile is not impaired.
JP-A-10-203429

  By the way, by shortening the front overhang length of the vehicle body, i.e., the length from the front wheel position to the vehicle front end in a side view, the yaw moment of inertia is effectively reduced and the vehicle performance is improved. In addition to typical effects, it is known that significant effects on design such as an increase in the stability of the appearance of an automobile and an appearance of the body of an FR sports car can be obtained.

  However, in recent years, in order to improve the safety at the time of collision, when designing the vehicle body, the front side frame has been extended in the front-rear direction, or a large reinforcement is built into the front bumper. Due to demands, it has been recognized that shortening the front overhang length is difficult.

  Therefore, in recent years, when the vehicle body is viewed from a direction other than right side (for example, obliquely rearward) with a sufficient front overhang length at the position of the front side frame in the vehicle width direction secured. The vehicle body is designed to increase the curvature of the front corner portion in plan view so that the portion overhang length is shortened.

  However, it is empirically known that a vehicle body having such a design has a higher air resistance than a conventional vehicle body having a small curvature at the front corner. Then, as a result of conducting research to clarify this factor, the inventors found that the state of the air flow entering the vehicle body from the front edge of the vehicle body differs depending on the curvature of the front corner portion. It was clarified that the difference has a dominant influence on the size of the air resistance of the car body.

  As shown in FIG. 13, it is known that several eddy currents are generated on the side of the vehicle body when the automobile travels. The vortex A shown in the figure is generated when a part of the air flowing along the front wind flows out to the side of the vehicle body beyond the front pillar (the pillar between the windshield and the side glass). Further, when the vehicle travels, the vortex B is wound upward as air flowing out from the space between the lower surface of the vehicle body and the road surface, the front wheel house, or the tire wheel to the side of the vehicle body flows backward. Has occurred. When the amount of air flowing out from the lower side of the vehicle body to the side of the vehicle body is large, the vortex B becomes larger as shown in FIG. 14A and the air flows out from the lower side of the vehicle body to the side of the vehicle body. When the amount of is small, it becomes small as shown in FIG. Then, as shown in FIG. 13, when the automobile moves forward, the above-described vortex B or vortex A flows to the rear of the vehicle body and is combined with a large separation of the flow at the rear end of the vehicle body, resulting in a large vortex flow. C is generated. The size of the eddy current C changes depending on the scale of the flow A and the eddy current B. When the eddy current B is large, the eddy current C also increases, and as a result, the Cd value of the vehicle body increases. (The Cd value is a value obtained by dividing the air resistance that the automobile receives during traveling by the front projection area of the automobile and the dynamic pressure (dynamic pressure of the air flow), and the lower the Cd value, the lower the air resistance. ing). Therefore, in order to reduce the Cd value, the amount of air flowing out from the bottom of the vehicle body to the side of the vehicle body must be reduced as much as possible to reduce the vortices B and C. The amount of air to be changed varies depending on the shape of the lower surface of the vehicle body at the front portion of the vehicle body and the flow of traveling wind flowing in the vicinity of the front surface of the vehicle body. Hereinafter, a description will be given with reference to FIGS.

  FIG. 15 shows the pressure distribution under the wing during the flight of a triangular wing aircraft.

  When a triangular wing aircraft flies, the pressure outside the wing is lower than the pressure inside the wing under the wing of the aircraft. This is because, as shown in FIG. 16, a vortex D that flows backward is generated outside the blade below the blade. Such a phenomenon also occurs under the vehicle body of the automobile during forward movement. When the automobile moves forward, as shown in FIG. 17, the vortex flow that flows backward on the outside in the vehicle width direction under the vehicle body. E has occurred.

  FIG. 18 is a diagram schematically showing an air flow generated below the front portion of the vehicle body as viewed from below the air flow when the automobile moves forward. 18, (a), (b), and (c) respectively show the lower surface of the vehicle body at the front portion of the vehicle body. The lower surface of the vehicle body shown in (a) has an angular shape, and the lower surface of the vehicle body shown in (c) is triangular. The lower surface of the vehicle body shown in (b) has an intermediate shape between (a) and (c).

  Thus, when the lower surface of the vehicle body has an angular shape as shown in (a), since the front edge of the vehicle body is straight, the flow of air entering from the front of the vehicle body to the lower part of the vehicle body front is reduced. Thus, the influence of the vehicle body front edge is almost uniform in the vehicle width direction. As a result, the air that has entered the lower portion of the front portion of the vehicle body flows rearward substantially linearly.

  Further, when the lower surface of the vehicle body has an intermediate shape shown in (b), since the vicinity of both ends of the vehicle width at the front edge of the vehicle body is curved, the same eddy current phenomenon as that below the triangular wing described above. Is generated under the vehicle body, and part of the air that has entered the lower part of the front part of the vehicle body becomes a vortex and flows to the rear of the vehicle body. This vortex flows gradually toward the outside of the vehicle width as it goes to the rear of the vehicle body, and it not only flows into the front wheel house 7 vigorously but also inside the vehicle width direction below the vortex under the vehicle body. It acts to suck the air flowing through. However, in the case where the lower surface of the vehicle body has the shape shown in (b), since the portion other than the vicinity of both ends of the vehicle width at the front edge of the vehicle body is linear, the scale of the eddy current is not so large. For this reason, the effect of the vortex on the air flowing under the vehicle body is not so great.

  Further, in the case where the lower surface of the vehicle body has the shape shown in (c), the outer edge portion of the vehicle body front edge portion tilts over the entire vehicle width direction center so that the vehicle body front edge portion has the vehicle width direction center. The triangular wing-like vortex phenomenon described above is prominently generated under the vehicle body because it has a bilaterally symmetric sharp tip. That is, a phenomenon occurs in which the above-described vortex flows in the vehicle width direction over the entire left and right regions under the vehicle body. As a result of this phenomenon, all the air that has entered the vehicle body from the front of the vehicle body becomes the vortex described above, and gradually flows outside the vehicle width toward the rear of the vehicle body. A vortex flows toward the front wheel house 7. For this reason, under the vehicle body, as shown by the broken line in the figure, the flow toward the vehicle width outer side becomes more dominant as the vehicle body is rearward. As a result, the amount of air Z flowing out from the lower side of the front wheel house 7 to the side of the vehicle body increases (see FIG. 17).

  Further, as shown in FIGS. 19 and 20, when the vehicle moves forward, traveling wind flows along the surface of the front bumper fascia 4, but as shown in FIG. The surface vicinity G is a region where the pressure is lower than the surface vicinity of other parts and the flow velocity of the traveling wind is reduced. For this reason, the traveling wind F passing through the vicinity of the surface G of the corner portion 12 is easily changed in flow direction by the surface shape of the corner portion 12. By being guided to the surface, a traveling wind F1 flowing obliquely downward with respect to the vehicle body can be generated. Then, when the traveling wind F1 is generated, the traveling wind F1 enters under the vehicle body, so that the amount of air flowing under the vehicle body increases. As a result, the vortex E below the vehicle body increases, and the large vortex E collides with the front wheel in the same manner as described above, so that the amount of air Z flowing out from the lower side of the front wheel house 7 toward the vehicle body side increases.

  As described above, when the vehicle is moving forward, the lower surface of the vehicle body at the front portion of the vehicle has a tapered shape, or a running wind is generated obliquely downward with respect to the vehicle body. The amount of air increases. Further, in order to remove the former factor, the lower surface of the vehicle body is angular as shown in FIG. 18A. As a result, the corner of the front part of the vehicle (specifically, the corner of the front bumper fascia 4 shown in FIGS. 19 and 20). If the part 12) is squared over the upper and lower ends, there arises a problem that the appearance of the automobile is impaired.

  Here, since the saddle-shaped projecting surface described in Patent Document 1 does not square the bottom surface of the vehicle body as shown in FIG. 18A, the amount of air flowing out from the bottom of the vehicle body to the side of the vehicle body is reduced. Not what you want.

  In the vehicle body shown in FIGS. 10 to 12, the skirt portion 100 can be effective as a means for making the lower surface of the vehicle body at the front of the vehicle square as shown in FIG. Therefore, as shown in FIG. 11, in the skirt portion 100, the vertical width h1 of the inner portion 101 in the vehicle width direction is smaller than the vertical width h2 of the outer portion 102 in the vehicle width direction. For this reason, the traveling wind F1 that flows obliquely downward with respect to the vehicle body by getting over the inner portion 101 in the vehicle width direction in the traveling wind F having a reduced flow velocity due to passing near the surface of the corner portion 12 is obtained. Can occur. Then, when the traveling wind F1 is generated, the vortex E increases as the traveling wind F1 enters under the vehicle body as described above, and the air that flows out from the lower side of the front wheel house 7 to the side of the vehicle body. The amount of Z increases.

  The present invention has been made in view of the above points, and the object of the present invention is to prevent the air flowing out from the bottom of the vehicle body to the side of the vehicle body when the vehicle moves forward without damaging the appearance of the front part of the vehicle. An object of the present invention is to provide an automobile front structure capable of reducing the amount.

  According to the first aspect of the present invention, by forming a skirt that bulges forward in the lower half of the front bumper, the lower surface of the vehicle body at the front of the automobile is squared without causing the upper half of the front of the automobile to be squared. It is designed to have a shape.

Specifically, the invention of claim 1 includes a front bumper fascia disposed below the front end of the bonnet, and a rear part extending rearward from the lower end of the front bumper fascia, with a rear part between the lower ends of the left and right front wheel wheel houses. Vehicle body front part structure having a flat plate-like under cover, and the lower half of the left and right corners of the front bumper fascia bulges forward from the upper half of the corners A skirt portion having an arcuate cross section is formed, and the skirt portion rises upward with a predetermined radius from the lower end of the corner portion with substantially the same radius of curvature, and in plan view, the outer periphery of the skirt portion The radius of curvature is 0.2 times the vehicle width and is smaller than the radius of curvature of the outer periphery of the corner at the center height of the front wheel ,
The upper end of the front Symbol skirt portion is located below the center height of the front wheel,
An opening is formed in the lower half of the vehicle width direction center of the front bumper fascia,
The skirt portion extends continuously in the vehicle width direction from the outer edge of the opening in the vehicle width direction to the front end of the front wheel house,
The vertical width of the skirt portion is 150 mm or more and 200 mm or less, and is uniform in the vehicle width direction,
The skirt portion includes an upper surface that allows traveling wind that has passed near the surface of the corner portion to flow to the side of the vehicle body.

  According to the present invention, since the above-described skirt portion is formed in the lower half of the corner portion, the lower surface of the vehicle body at the front portion of the automobile exhibits an angular shape.

  In addition, since the skirt portion rises with a predetermined width from the lower end of the corner portion with substantially the same radius of curvature, the vertical width of the skirt portion is uniform in the vehicle width direction. Become. As a result, by appropriately setting the vertical width of the skirt portion, when the vehicle body moves forward, the traveling wind that has passed near the surface of the corner portion moves sideways along the upper surface of the skirt portion. It flows over the skirt and does not flow diagonally downward with respect to the vehicle body over the skirt.

  From the above, when the automobile moves forward, the eddy current flowing outside in the vehicle width direction under the vehicle body becomes small. For this reason, the amount of air flowing out from the lower side of the front wheel house to the side of the vehicle body is reduced by the collision of the vortex with the front wheel. As a result, the eddy current generated at the side of the vehicle body or at the rear of the vehicle body becomes small, and the Cd value of the vehicle body becomes low.

  Also, no skirt portion is formed in the upper half of the front bumper fascia that has a large visual impact. Thereby, since the upper part of the front bumper fascia is not angular, the appearance of the front part of the automobile is not impaired.

Further, the outer periphery of the skirt, shape der along an arc having 0.2 times the radius of curvature of the vehicle width, than the radius of curvature of the corner portion outer peripheral radius of curvature at the center height of the front wheel since even small, traveling wind, without flowing obliquely downward relative to the vehicle body rides over the skirt portion, which is advantageous in obtaining the above effect flowing toward the side of the vehicle body along the upper surface of the skirt portion.

  Further, since the upper end of the skirt portion is positioned below the center height of the front wheel wheel, that is, in the corner portion of the front bumper fascia, the skirt portion is not formed above the center height of the front wheel wheel. In the front bumper fascia, the portion above the center height of the front wheel that has a large visual influence is not angular.

  An opening is formed in the lower half of the front bumper fascia in the vehicle width direction center, and the skirt portion extends from the outer edge of the opening in the vehicle width direction to the front end of the front wheel arch. When the vehicle advances forward, the traveling wind that flows between the outer edge of the opening in the vehicle width direction and the front end of the front wheel arch is moved by the skirt to the vehicle body. In contrast, it is restricted to flow obliquely downward.

  Moreover, since the width | variety in the up-down direction of the said skirt part is 150 mm or more and 200 mm or less, the said effect can be acquired, without impairing the external appearance of a motor vehicle front part.

  According to the present invention, when the automobile moves forward, the upper surface of the skirt portion is restricted so that the traveling wind flowing from the outer edge of the opening portion toward the front end of the front wheel arch flows obliquely downward above the skirt portion, Since the vortex flow that flows outside in the vehicle width direction under the vehicle body becomes small, the amount of air flowing out from the vehicle body side to the vehicle body side decreases. As a result, the eddy current generated at the side of the vehicle body or at the rear of the vehicle body becomes small, and the Cd value of the vehicle body becomes low.

  In addition, since the upper half of the front bumper fascia, which has a large visual impact, is not angular, the appearance of the front part of the automobile is not impaired.

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

  FIG. 1 is a perspective view showing a front part of an automobile according to the present invention, FIG. 2 is a side view showing the front part of the automobile according to the present invention, and FIG. FIG. 4 is an enlarged perspective view showing the front part of the automobile according to the present invention.

  Reference numeral 1 denotes an automobile according to the present embodiment, and the left side in FIGS.

  As shown in FIGS. 1 and 2, the front portion of the automobile 1 includes a hood 2 that covers the engine room, a pair of sheet metal front fenders 5 that are disposed on both outer sides in the vehicle width direction with respect to the hood 2, and And a resin front bumper facer 4 disposed below the bonnet front end 3 and the front fender front end 24.

  The front bumper fascia 4 extends in the vehicle width direction, and the outer edge 17 in the vehicle width direction of the front bumper fascia 4 and the lower edge 50 of the front fender 5 located behind the front bumper fascia 4 accommodate the upper part of the front wheel 6. An arch-shaped front wheel wheel house 7 is configured.

  An opening 10 is provided in the lower half of the front bumper fascia 4 in the vehicle width direction center 40 (hereinafter simply referred to as the center 40), and a front under grill 11 is fitted into the opening 10. The front under grill 11 has a mesh shape, and this mesh structure allows outside air to be introduced into the engine room. Further, a recess 8 is formed above the opening 10 in the central portion 40, and a front grill 9 having a gap for guiding outside air into the engine room is attached to the recess 8.

  Further, in the front bumper fascia 4, an opening 13 is formed in the left and right corner portions 12 located outside the vehicle width of the central portion 40, and a dummy grille 14 as a decoration is fitted in the opening 13. ing.

  Further, as shown in FIG. 3, the lower portion of the automobile 1 has a flat plate-like shape that extends rearward from the lower end portion 23 of the front bumper fascia 4 and the rear portion is positioned between the lower ends 70 of the left and right front wheel wheel houses 7. An under cover 15 is disposed. In the present embodiment, the lower surface of the front bumper fascia 4 and the lower surface of the under cover 15 positioned behind the front bumper facer 4 constitute a vehicle body lower surface 28 at the front of the automobile.

  Thus, in the lower half of the left and right corner portions 12 of the front bumper fascia 4, a skirt portion 16 having an arcuate cross section that bulges forward from the upper half portion of the corner portion 12 is formed.

  The skirt portion 16 rises upward from the lower end 18 of the corner portion 12 with a predetermined width. The skirt portion 16 rises from the lower end 18 of the corner portion 12 with substantially the same radius of curvature R1. The radius of curvature R1 of the skirt portion 16 is equal to that of the corner portion 12 at the center height 20 of the front wheel 6. It is smaller than the curvature radius R2.

  Since the skirt portion 16 is provided in the lower half portion of the corner portion 12, the lower surface 28 of the vehicle body has an angular shape as shown in FIG.

  Also, as shown in FIG. 4, since the skirt portion 16 rises from the lower end 18 with substantially the same radius of curvature R1 as described above, unlike the skirt portion 100 shown in FIGS. As shown, the vertical width h of the skirt portion 16 is uniform in the vehicle width direction. Thus, by appropriately setting the vertical width h, when the automobile 1 moves forward, the traveling wind F that has passed near the surface of the corner portion 12 of the front bumper fascia 4 (See FIGS. 1 to 3), and does not flow obliquely downward with respect to the vehicle body over the skirt portion 16 as shown by F1 in FIGS.

  From the above, when the automobile 1 moves forward, the eddy current E flowing outside the vehicle width under the automobile 1 becomes small. Therefore, the eddy current E collides with the front wheel 6 so that the vehicle body can be seen from below the front wheel house 7. The amount of air Z flowing out to the side is reduced. As a result, the eddy current B generated on the side of the vehicle body shown in FIG. 13 is reduced, and accordingly, the eddy current C generated at the rear of the vehicle body is also reduced, so that the Cd value of the automobile 1 is reduced.

  Also, the upper half 21 (see FIGS. 1 and 2) of the corner 12 positioned above the center height 20 of the front wheel 6 is a visually significant part, but as shown in FIG. The upper end 19 of the skirt portion 16 is positioned below the center height 20 of the front wheel 6, and the skirt portion 16 is not formed in the upper half portion 21. For this reason, the upper half part 21 of the corner part 12, more specifically, the part above the center height 20 of the front wheel 6 in the corner part 12 is not angular. Thereby, the appearance of the front part of the automobile 1 is not impaired by the skirt portion 16 being provided in the corner portion 12.

  In the present embodiment, the skirt portion 16 is continuous in the vehicle width direction from the outer edge 26 of the opening 10 in the vehicle width direction to the front end 17 of the front wheel house 7 (the edge 17 of the front bumper fascia 4). It extends. As a result, when the automobile 1 moves forward, the traveling wind F flowing between the outer edge 26 of the opening 10 and the front end 17 of the front wheel house 7 above the skirt portion 16 is applied to the vehicle body by the skirt portion 16. To flow downward and obliquely.

  Next, examples of the present invention will be described.

  As an example of the present invention, the automobile 1 of the above embodiment was manufactured, and a wind tunnel experiment was conducted to confirm the state of air flowing near the surface of the automobile 1.

  FIG. 5 is a photograph of the front part of the automobile according to this example.

  In manufacturing the automobile 1 of the present embodiment, the vertical width h of the skirt portion 16 is set to a predetermined value within a range of 150 mm or more and 200 mm or less.

  FIG. 6 is a diagram illustrating the outer periphery W of the automobile in the height range where the skirt portion is formed in the present embodiment.

When fabricating the automotive 1, arc curvature radius R1 of the circular arc K along the outer periphery of the skirt portion 16, it becomes 0.2 times the vehicle width l, it extends from the vehicle body front end 25 on the vehicle width center line Y K The angle θ formed by the aperture angle line N, which is a tangent to the vehicle, and the vehicle width direction M is set to 10 degrees. Z in the figure is a camber angle line Z in contact with the arc K at the front end of the front wheel house 7 (end edge 17 of the front bumper fascia 4) .

  Then, with the tuft 22 installed on the front surface of the automobile 1, wind was blown from the front to the automobile 1. FIG. 5 shows the state of the tuft 22 after blowing wind. After blowing wind on the automobile 1, the tuft 22 installed above the skirt portion 16 extends substantially parallel to the upper surface of the skirt portion 16. From this, it was confirmed that the air that passed above the skirt portion 16 did not flow obliquely downward with respect to the vehicle body.

  Moreover, when the automobile 1 of the present embodiment moved forward, the state of the air flowing under the vehicle body was grasped by simulation.

  FIG. 7 is a simulation prediction diagram showing the state of the air flow under the vehicle body of the present embodiment, in which the left side is the front side of the automobile 1, and the lines shown in the figure are the air flow lines under the vehicle body. Show.

  According to the simulation, it was predicted that air would flow substantially parallel to the side surface 60 of the front wheel 6 on the outer side in the vehicle width direction under the vehicle body of the present embodiment, and it was not predicted that a large vortex E would be generated. For this reason, it has been found that the amount of air flowing out from the lower side of the front wheel house 7 to the side of the vehicle body decreases as the vortex E collides with the front wheel 6.

  Further, when the automobile 1 of this embodiment moves forward in order to grasp the state of the vortex generated on the side of the vehicle body based on the fact that the pressure at the location where the eddy current is generated becomes smaller than the pressure at the non-occurrence location, the automobile 1 The pressure distribution occurring on the side of the was predicted by simulation. Further, for comparison, the pressure distribution generated on the side of the vehicle body when the vehicle having the shape obtained by removing the skirt portion 16 from the vehicle 1 of the present embodiment moves forward under the same conditions was predicted by simulation. In the vehicle of this comparative example, the lower surface of the vehicle body at the front of the vehicle has a tapered shape as shown in FIG.

  FIG. 8 is a diagram showing the predicted position of the pressure distribution on the side of the vehicle body, and the left side in FIG. 8 shows the front side of the vehicle body.

  Three positions (O, P, and Q) were selected on the sides of the front wheel house 7 as predicted positions of the pressure distribution.

  FIG. 9 is a simulation prediction diagram showing the pressure distribution at the predicted position shown in FIG. 8, where (a) shows the pressure distribution on the side of the vehicle body of the present embodiment, and (b) shows the pressure distribution on the side of the vehicle body of the comparative example. The pressure distribution is shown.

  As is clear when the pressure distributions at the same predicted position are compared, it is predicted that the low pressure region is narrower at the predicted position of this embodiment than at the predicted position of the comparative example. As a result, it was found that the vortex generated on the side of the vehicle body is reduced by providing the skirt portion 16 and making the lower surface of the vehicle body at the front of the vehicle square.

It is a perspective view which shows the motor vehicle front part of this invention. It is a side view which shows the motor vehicle front part of this invention. It is a perspective view which shows the vehicle body lower surface of the motor vehicle front part of this invention. It is a perspective view which expands and shows the automobile front part of the present invention. It is the photograph which image | photographed the motor vehicle front part in the Example of this invention. In this example, it is a figure which shows the outer periphery of the motor vehicle in the height range in which the skirt part was formed. It is a simulation prediction figure which shows the state of the air flow under the vehicle body of a present Example. It is a figure which shows the prediction position of the pressure distribution in a vehicle body side. It is a simulation prediction figure which shows the pressure distribution in the prediction position shown in FIG. It is a perspective view which shows the conventional vehicle front part structure. It is a side view which shows the conventional vehicle front part structure. It is a perspective view which shows the vehicle body lower surface of the conventional automobile front part structure. It is a figure which shows the flow of the air which arises in the side and back of a vehicle body, when a motor vehicle advances. It is a figure which shows the eddy current which arises in the side of a vehicle body, when a motor vehicle advances. It is a figure which shows the pressure distribution under the wing | blade in the flight of the aircraft of a triangular wing. It is a figure which shows the state of the eddy current which arose under the wing during the flight of the aircraft of a triangular wing. It is a figure which shows the state of the eddy current which flows the vehicle width outer side under a vehicle body at the time of advancing of a motor vehicle. It is a figure which shows the flow of the air under a vehicle body at the time of the advance of a motor vehicle. It is a perspective view which shows the state of the driving | running | working wind which flows the surface vicinity of the front part of a motor vehicle at the time of advancing of a motor vehicle. It is a side view which shows the state of the driving | running | working wind which flows the surface vicinity of the front part of a motor vehicle at the time of advancing of a motor vehicle. It is a figure which shows the pressure distribution of the surface vicinity of the front part of a motor vehicle at the time of advancing of a motor vehicle.

1 car,
3 Front end of bonnet,
4 Front bumper fascia,
6 Front wheel,
7 Front wheel house,
10 opening,
12 Corner part,
15 Undercover,
16 Skirt,
18 Lower corner,
20 Center height,
23 Lower edge of front bumper fascia,
26 Outer edge,
28 underside of the car body,
30 Rear wheel house,
70 The lower end of the front wheel house,
h Vertical width,
N aperture angle line,
Z camber angle line,
K arc,
R1 radius of curvature.

Claims (1)

A vehicle body having a front bumper fascia disposed below the front end of the bonnet, and a flat plate-like undercover extending rearward from the lower end of the front bumper fascia and having a rear portion positioned between the lower ends of the left and right front wheel wheel houses A front structure,
In the lower half of the left and right corner portions of the front bumper fascia, a skirt portion having an arcuate cross section bulging forward from the upper half portion of the corner portion is formed,
The skirt portion rises with a substantially same curvature radius upward from the lower end of the corner portion with a predetermined width,
In plan view, the radius of curvature of the outer periphery of the skirt portion is 0.2 times the vehicle width, and is smaller than the radius of curvature of the outer periphery of the corner portion at the center height of the front wheel ,
The upper end of the front Symbol skirt portion is located below the center height of the front wheel,
An opening is formed in the lower half of the vehicle width direction center of the front bumper fascia,
The skirt portion extends continuously in the vehicle width direction from the outer edge of the opening in the vehicle width direction to the front end of the front wheel house,
The vertical width of the skirt portion is 150 mm or more and 200 mm or less, and is uniform in the vehicle width direction,
The front structure of the vehicle body, wherein the skirt portion includes an upper surface that allows the traveling wind that has passed near the surface of the corner portion to flow to the side of the vehicle body.