JP2000185672A - Rear part lower surface side structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear part lower surface side structure of a vehicle capable of smoothly cooling drive elements, and reducing turbulence of air generated on the back of the vehicle. SOLUTION: A saddle-shaped fuel tank 5 is provided between front and rear axles, and a differential gear 6 is provided at a backward position from the fuel tank 5 to be positioned under a rear floor panel 7 composing a car body. Under the differential gear 6, a rear undercover main body 19 is provided to cover the rear part lower surface side of a vehicle to be apart from the rear floor panel having an inclined surface part 19c extended to be inclined so as to rise backward, and an air intake gap 30 is formed. A ventilation passage 31 is provided, a rear end edge part 19e of the inclined surface part 19c is set to be apart from a rear bumper member lower edge part 16a, and an air suction gap 32 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear lower surface structure of a vehicle provided with a rear under cover on the rear lower surface of the vehicle.

[0002]

2. Description of the Related Art A conventional rear lower surface structure of a vehicle includes:
For example, the one shown in FIG. 8 is known.

[0003] In such a vehicle, a fuel tank 5 is provided in front of a rear lower surface 2 of the vehicle 1 and between rear axles 3 and 4. A differential gear 6 as a driving element is provided below the rear floor panel 7 behind the fuel tank 5.

[0004] The rear floor panel 7 has a storage recess 7 a for a spare tire 9 stored in a trunk room 8.
Are formed so as to protrude downward.

[0005] A rear bumper member 11 is provided at the rear end of the vehicle 1.
Is extended downward to the rear lower surface 2.

[0006]

However, in such a conventional rear lower surface structure of the vehicle 1, a part A1 of the air A introduced into the lower surface from the front of the vehicle is partially removed by the storage recess 7a. As a result, it is caught and stays in the differential upper space 12.

The lower end 11 of the rear bumper member 11
Since a is extended downward, another part A2 of the air A is wound up and stays in the front space of the bumper.

Further, in the rear of the vehicle 1, a part A3 of the air A that has flowed out from the rear lower surface 2 is disturbed so as to wind up.
It increases the resistance.

For this reason, there has been a problem that the air A that has cooled the fuel tank 5 and the differential gear 6 is not easily ventilated to the rear of the vehicle.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle having a rear lower surface structure capable of solving the above-mentioned problems and smoothly cooling a driving element and reducing turbulence of air generated behind the vehicle. To provide.

[0011]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a rear part of a vehicle is provided below a driving element located behind a fuel tank between axles of the vehicle. A rear lower surface structure of a vehicle having a rear under cover main body provided so as to cover a lower surface side, wherein the rear under cover main body is spaced apart from the vehicle lower surface side, and is located in a vehicle forward position with respect to the drive element. In addition, an air intake gap is formed by locating the front edge of the rear under cover main body, and a ventilation path is provided between the drive element and the rear under cover main body to constitute a part of the ventilation path. An inclined surface rising upward is provided on the rear under cover main body,
Further, the present invention is characterized by a rear lower surface structure of a vehicle in which an air suction port is formed behind the inclined surface.

According to the first aspect of the present invention, the air intake gap formed between the front edge of the rear under cover main body and the lower surface of the vehicle at a position forward of the drive element with respect to the vehicle. The air partially flows and is introduced between the upper surface of the rear under cover main body and the lower surface of the vehicle.

On the other hand, the air passing below the rear under cover main body generates a negative pressure region at a position rearward of the vehicle by the inclined surface portion of the rear under cover main body.

Therefore, the diverted air passes through the air passage formed between the drive element and the rear undercover main body, and is smoothly sucked from the air suction port.

Therefore, the drive element is cooled smoothly, and the turbulence of air generated behind the vehicle is reduced.

According to a second aspect of the present invention, the front edge is provided at a position more rearward of the vehicle than a front end of a kick-up portion of a rear floor panel of the vehicle.
The vehicle has a rear lower surface side structure described in the above.

According to the second aspect of the present invention, since the front edge is provided at a position behind the kick-up portion front end of the rear floor panel of the vehicle, the front edge is introduced to the lower surface of the vehicle. The generated air is guided upward along the rear floor panel by the kick-up portion front end, and generates a front negative pressure region in front of the axle.

Therefore, air can be smoothly introduced from the air intake gap.

Further, when the fuel tank is arranged in a concave portion formed by the kick-up portion, the periphery of the fuel tank is cooled by air guided upward along the rear floor panel. Is done.

Further, according to the third aspect of the present invention, the front end edge is provided at a height position lower than a height position which is a minimum height position above the ground of a rear floor panel of the vehicle. 2 is characterized by a rear lower surface side structure of the vehicle.

According to the third aspect of the present invention, the front edge is provided at a height lower than the lowest height of the rear floor panel of the vehicle. The air introduced into the lower surface of the vehicle along the rear floor panel can be smoothly diverted to both the upper and lower surfaces of the rear undercover main body.

And, according to the fourth aspect,
The rear lower surface side structure of a vehicle according to any one of claims 1 to 3, wherein a polygonal line forming a front end edge of the inclined surface portion is located rearward of the vehicle with respect to the drive element.

According to the fourth aspect of the present invention, the polygonal line forming the front edge of the inclined surface is located rearward of the vehicle with respect to the drive element.

Therefore, the flow of air sent to the driving element can be further smoothed.

According to a fifth aspect of the present invention, the mudguard vertical wall is provided on a side edge of the rear undercover main body so as to extend upward from the vehicle. The vehicle has a rear lower surface side structure described in any one of the above aspects.

According to the fifth aspect of the present invention, a mudguard vertical wall is provided on the side edge of the rear undercover main body so as to extend upward from the vehicle. Therefore, there is no need to project the mudguard member downward,
Furthermore, the turbulence of the air generated behind the vehicle can be reduced by flattening the lower surface side of the vehicle.

According to a sixth aspect of the present invention, an air intake opening for introducing air below the driving element is formed in the rear under cover main body substantially at the center in the vehicle width direction. A rear lower surface side structure of a vehicle according to any one of claims 1 to 5, characterized by the above-mentioned.

According to the sixth aspect of the present invention, the air introduced from the air intake opening is:
It is guided below the drive element and is sucked from the ventilation path to the rear of the vehicle.

For this reason, the amount of cooling air passing below the driving element can be increased, and the cooling efficiency can be further improved.

[0030]

First Embodiment A first embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 7 show a first embodiment of the present invention.
It shows. Parts that are the same as or equivalent to those in the conventional example will be described with the same reference numerals.

First, the structure will be described. In the structure of the rear lower surface of the vehicle 14 according to the first embodiment, the front and rear axles 3, 4
Between them, a saddle-shaped fuel tank 5 through which the center shaft 15 is inserted is provided substantially on the lower side of the center. At a position behind the fuel tank 5, a differential gear 6 as a driving element is connected to the center shaft 15 and provided below the rear floor panel 7 constituting the vehicle body.

The rear floor panel 7 has a storage recess 7 a for a spare tire 9 stored in a trunk room 8.
Are formed so as to protrude downward.

The rear floor panel 7 is provided with a kick-up portion 7b for accommodating the fuel tank 5 in a recess formed on the lower surface side.

A rear bumper member 16 is mounted on the rear end of the vehicle 1. This rear bumper member 16
A part of the rear surface lower end edge 16a is formed in an inverted concave shape so as to partially project a muffler 18 provided at the rear end of an exhaust pipe 17 extending along the vehicle front-rear direction. ing.

Below the differential gear 6, a rear under cover main body 19 is provided so as to cover the rear lower surface of the vehicle.

The rear under cover main body 19 is made of a flat plate made of carbon resin whose rigidity is improved by exhibiting a honeycomb shape in a cross section along a substantially horizontal cross section. As shown in FIGS. A horizontal plane portion 19a fixed substantially parallel to the surface of the earth, and a predetermined angle α (about 9 to 10 ° in this embodiment) is provided on the horizontal plane portion 19a via a polygonal line 19b so as to be inclined upward and backward. Inclined surface portion 19c
It is composed of

In the rear under cover body 19, as shown in FIG. 4, a pair of left and right front brackets 21 and 21 mounted on the vehicle body side rear suspension mount brackets 20 and 20 have a front end edge 19d. It is fixed to a reinforcing member 22 extending in the width direction.

The front edge 19d is, as shown in FIG.
Kick-up portion 7 of rear floor panel 7 of vehicle 14
b Provided at a position behind the front end 7c in the vehicle.

The front edge 19d is connected to the vehicle 14
Height h1, which is the minimum ground clearance of the rear floor panel 7
It is provided at a lower height position h2, and is configured to be higher than the approach angle line AP of the rear wheel RW.

A pair of left and right side edge brackets 23 are provided near both side edges of the inclined surface portion 19c of the rear under cover body 19.

The side edge brackets 23, 23 each have a substantially O-shaped cross section, and as shown in FIG. 3, the rear fender panel members 24, 24 joined to the side edges 7c, 7c of the rear floor panel 7. The upper sides 23a and 23b are welded and fixed to the vicinity of the lower edge.

The lower side portions 23c, 23c of the side edge brackets 23, 23, together with the left and right mudguard vertical walls 25, 26, which are erected from both side edges of the inclined surface portion 19c toward the upper side of the vehicle, They are fastened together by bolt members 27, 27 and nut members 28, 28.

Further, a rear bracket 29 having a substantially hat shape as viewed from the front is fixed to the rear under cover main body 19 near the rear end edge 19e of the inclined surface portion 19c.

The upper portion 29a of the rear bracket 29 substantially at the center in the vehicle width direction is welded and fixed to the storage recess 7a of the rear floor panel 7, so that the rear under cover main body 19 is mounted on the lower surface of the vehicle. As shown in FIG. 1, the air intake gap 30 is formed at the front side of the vehicle, at a position forward of the differential gear 6 with the front end edge 19 d of the rear undercover main body 19 positioned apart from the rear floor panel 7. ing.

Also, the differential gear 6,
A ventilation path 31 is provided between the rear under cover main body 19 and the rear under cover main body 19.
Is provided, and the lower surface side of the ventilation passage 31 is closed by the horizontal surface portion 19a and the inclined surface portion 19c.

Further, the rear end edge portion 19 of the inclined surface portion 19c
e is separated from the lower edge 16a of the rear bumper member 16 to form an air / water discharge gap 32 as an air suction port.

Further, in the first embodiment, the broken line 19b constituting the front end of the inclined surface portion 19c is larger than the rear axle 4 which is the center of rotation of the differential gear 6.
It is configured such that it is located behind the vehicle by a predetermined distance L.

Further, in the first embodiment, an air intake opening 33 for introducing air which comes into contact with the differential gear 6 is formed in the horizontal plane portion 19a of the rear under cover main body 19 substantially at the center in the vehicle width direction. ing.

An exhaust pipe notch 34 is formed at a position corresponding to the exhaust pipe 17 from the horizontal surface portion 19a of the rear under cover body 19 to a part of the inclined surface portion 19c.

Further, in the vicinity of the rear end edge 19e of the inclined surface portion 19c of the rear under cover main body 19, a cutout portion 35 for a muffler is formed by partially cutting out the muffler 18 so as to project the muffler 18. The rear under cover main body 19 has a rear end edge 19e formed with a notch 36 for routing which is partially cut out to project the tow bracket.

Further, in the first embodiment, a plurality of rectifying fin members 37 and 38 are provided on the lower surface side of the rear under cover main body 19 so as to extend in the vehicle longitudinal direction.

The lower edges of these fin members 37, 38
Above the departure angle line DP of the rear wheel RW,
In addition, the fin members 38 are located along the departure angle line DP, and the fin members 38 on both sides of the fin members are located substantially along the rear extension direction of the inner surface of the rear wheel RW on the vehicle center side. One of the central fin members 37 is located substantially along the rear extension direction of the exhaust pipe cutout portion 34 of the rear undercover main body 19.

Next, the operation of the first embodiment will be described.

In the first embodiment, the air intake formed between the front edge 19d of the rear under cover main body 19 and the rear floor panel 7 constituting the lower surface of the vehicle at a position forward of the differential gear 6 in the vehicle. A part of the air introduced into the lower part of the vehicle 14 is diverted from the gap 30, and the air passage 3 formed between the upper surface of the rear under cover main body 19 and the lower surface of the rear floor panel 7 is formed.
1 is introduced.

On the other hand, the air passing below the rear under cover main body 19 generates a negative pressure region from the broken line 19b to the vehicle rear position by the inclined surface portion 19c of the rear under cover main body 19. In particular, near the rear edge 16a of the rear undercover main body 19, a further negative pressure range H1 is provided.
Occurs.

Therefore, the diverted air passes through the air passage 31 formed between the differential gear 6 and the rear under cover main body 19, and is smoothly sucked from the air suction gap 32. Will be issued. At this time, the air whose temperature around the differential gear 6 has increased is also entrained and discharged at the same time.

Therefore, the cooling of the differential gear 6 is performed smoothly, and the air that has passed under the rear under cover body 19 is also rectified by the sucked air and is generated behind the vehicle. Air turbulence is reduced.

The front edge 19d is connected to the vehicle 14
Is provided at a position rearward of the vehicle from the front end 7c of the kick-up portion 7b of the rear floor panel 7 so that the air introduced to the lower surface side of the vehicle can prevent the front edge 1
By 9d, it is guided upward along the rear floor panel 7.

Therefore, the air intake gap 3
Air can be smoothly introduced from zero.

Further, since the fuel tank 5 is arranged in the concave portion on the lower surface side of the vehicle formed by the kick-up portion 7b, the air guided upward along the rear floor panel 7 allows the fuel The periphery of the tank 5 is cooled.

Further, in the first embodiment, the exhaust pipe 17 and the muffler 18 are located in the ventilation passage 31 on the upper surface side of the rear under cover main body 19. Therefore, the air around the exhaust pipe 17 and the muffler 18 is also smoothly sucked toward the rear of the vehicle from the air suction gap 32 in the direction of the negative pressure region H1 and cooled.

Therefore, unlike the related art, the hot air is wound up around the differential gear 6 or in front of the rear bumper member 16 and does not stay there.
In addition to smoothly cooling the driving elements, it is possible to reduce the turbulence of air generated at the rear of the vehicle, and to provide a desired downforce to the rear axle 4 and achieve a high-dimensional balance of reducing the resistance value. I can do it.

Further, the front edge 19d and a height position h which is the lowest height above the ground of the rear floor panel 7 of the vehicle 14.
1, the air introduced into the lower surface of the vehicle along the rear floor panel 7 is smoothly diverted to both the upper and lower surfaces of the rear under cover main body 19. I can do it.

The broken line 19b forming the front edge of the inclined surface portion 19c is connected to the differential gear 6
Than a predetermined distance L behind the vehicle.

Therefore, the differential gear 6
In the ventilation passage 31 located below the horizontal plane portion 19
The path of the air passing substantially horizontally along the line a can be set to be long, the suction efficiency can be improved, and the air flow can be made smoother.

Further, in the first embodiment, by positioning the broken line 19b behind the differential gear 6 by a predetermined distance L, the inclination angle α at which the inclined surface portion 19c rises rearward can be increased. The balance between the ventilation resistance of the rear lower surface portion of the vehicle and the downforce due to the negative pressure can be set to approximately 9 to 10 degrees, which is the optimum condition. In addition, the inclination angle α is also an angle at which the appearance quality is good when an eye point spaced away from the vehicle is placed. In this way, by extending the horizontal surface portion 19a and positioning the position of the broken line 19b behind the vehicle by a predetermined distance L, it is optimal for the inclined surface portion 19c regardless of the overhang length of the rear portion of the vehicle 14. Angle can be given.

In the first embodiment, the left and right mudguard vertical walls 2 are provided on both side edges of the rear undercover main body 19.
5, 26 are erected toward the upper part of the vehicle. Therefore, it is not necessary to protrude the mudguard member downward from the rear edge of the rear tire house, and furthermore, the lower surface side of the vehicle 14 can be flattened, and the turbulence of the air generated behind the vehicle can be reduced.

Further, in the first embodiment, the air introduced from the air intake opening 33 is guided below the differential gear 6 and is introduced from the air intake gap 30 passing through the ventilation passage 31. At the same time, it is sucked to the rear of the vehicle.

Therefore, the differential gear 6
By increasing the amount of cooling air passing below the air conditioner, the cooling efficiency can be further improved.

Further, in the first embodiment, a plurality of rectifying fin members 37 and 38 are provided on the lower surface side of the rear under cover main body 19 so as to extend in the vehicle longitudinal direction.

For this reason, it passes under the rear undercover main body 19 between the two rear wheels RW, and the exhaust pipe notch 34, the rear wheel RW and the rear undercover main body 19
The flow of the air, whose flow is turbulent due to the notch for the rear wheel RW, can be divided into a right flow AR, a center flow AC, and a left flow AL below the inclined surface portion 19c and rectified. The amount of air entering the negative pressure range H1 from the side of the vehicle can be reduced, and the turbulence of air generated behind the vehicle can be further reduced.

Therefore, each of the divided air flows A
Since R, AC, and AL are less likely to enter the adjacent flow region in the setting region of the fin members 37, 38, the effectively separated air flow can be used in the negative pressure generation region of the inclined surface portion 19C. A desired downforce can be obtained.

Further, since the fuel tank 5, the differential gear 6, the muffler 18 and the like provided at the lower part of the vehicle 14 are partially or entirely covered by the rear under cover body 19, damage and the like are prevented.

Although the first embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to the first embodiment, and there may be design changes within the scope of the present invention. Even this is included in the present invention.

For example, in the first embodiment, the front edge 19d is provided at a position behind the front end 7c of the kick-up portion 7b of the rear floor panel 7 of the vehicle 14, but the present invention is not limited to this. For example, the front edge 1
9d may be provided at substantially the same position as the front end 7c of the kick-up portion 7b or at a position in front of the vehicle.

In the first embodiment, the front edge 19d is provided at a height position h2 which is lower than the height position h1 which is the lowest height of the rear floor panel 7 of the vehicle 14 above the ground. The present invention is not particularly limited to this. For example, the front edge portion 19d is placed at a substantially same height position or a height position higher than the height position h1 by utilizing a shape recessed below the kick-up portion 7b. It may be provided.

Further, the front edge 19d of the inclined surface portion 19c
Is located a predetermined distance L behind the position of the rear axle 4 of the differential gear 6 in the vehicle, but the present invention is not limited to this.
9b may coincide with the rear axle 4 or be provided in front of the rear axle 4.

The rear end edge 19e of the rear undercover main body 19 and the rear bumper member 16 which do not need to open the air suction gap 32 as an air suction port.
Although the gap is formed in the gap with the lower edge portion 16a, the invention is not limited to this. For example, a dedicated opening may be separately provided in the rear bumper member 16 or the like.

The left and right mudguard vertical walls 25 and 26 are provided on the side edges of the rear under cover main body 19 so as to extend upward from the vehicle. In particular, the left and right mudguard vertical walls 25 and 2 are provided.
6 may not be provided.

Further, the differential gear 6 is provided substantially at the center of the rear under cover body 19 in the vehicle width direction.
Single air intake opening 33 for introducing air below
However, the shape, quantity, material, and the like of the air intake openings, such as forming a plurality of air intake openings 33, are not particularly limited to the first embodiment. Obviously, the intake opening 33 need not be provided.

Further, in the first embodiment, a plurality of rectifying fin members 37, 38 are provided on the lower surface side of the rear under cover main body 19 along the vehicle front-rear direction. The shape, quantity, material and the like are not limited. For example, these rectifying fin members 37 and 38 are used.
Needless to say, it is not necessary to provide.

In the first embodiment, the description is made using the FR vehicle 14. Therefore, the differential gear 6 is shown as the driving element. However, the present invention is not limited to this. It may be a rigid axle or the like used for the rear axle of the FF vehicle.

[0084]

As described above, according to the first aspect of the present invention, at a position in front of the driving element in the vehicle,
The air partially flows from an air intake gap formed between the front edge of the rear under cover main body and the vehicle lower surface side and is introduced between the rear under cover main body upper surface side and the vehicle lower surface side. .

On the other hand, the air passing below the rear under cover main body generates a negative pressure region at a position rearward of the vehicle due to the inclined surface portion of the rear under cover main body.

Therefore, the diverted air passes through the ventilation path formed between the drive element and the rear under cover main body, and is smoothly sucked from the air suction port.

Therefore, the drive element is cooled smoothly, and the turbulence of air generated behind the vehicle is reduced.

According to the second aspect of the present invention, since the front edge is provided at a position behind the kick-up portion front end of the rear floor panel of the vehicle, the air introduced into the lower surface of the vehicle is The kick-up portion is guided upward along the rear floor panel by the front end of the kick-up portion, and generates a front negative pressure region in front of the axle.

Therefore, air can be smoothly introduced from the air intake gap.

When the fuel tank is disposed in the concave portion formed by the kick-up portion, the periphery of the fuel tank is cooled by air guided upward along the rear floor panel. Is done.

Further, according to the third aspect of the present invention, the front edge is provided at a height lower than the lowest height of the rear floor panel of the vehicle, which is the minimum height above the ground. The air introduced along the lower surface of the vehicle along the lower under cover body can be smoothly diverted to the upper and lower surfaces of the rear under cover main body.

[0092] According to the fourth aspect of the present invention, the broken line forming the front edge of the inclined surface portion is located rearward of the vehicle with respect to the drive element.

Therefore, the flow of air sent to the driving element can be further smoothed.

According to the fifth aspect of the present invention, a mudguard vertical wall is provided on a side edge portion of the rear under cover main body so as to extend upward from the vehicle. Therefore, it is not necessary to protrude the mudguard member downward, and furthermore, the lower surface side of the vehicle can be flattened, and the turbulence of the air generated behind the vehicle can be reduced.

Further, according to the sixth aspect of the present invention, the air introduced from the air intake opening is guided below the driving element, and is sucked from the ventilation path to the rear of the vehicle.

For this reason, the amount of cooling air passing below the driving element can be increased, and the cooling efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a vehicle rear lower surface side structure according to a first embodiment of the present invention, in which a vehicle rear portion is viewed from a side.

FIG. 2 is a perspective view of the entire rear surface of the vehicle according to the first embodiment, viewed from obliquely rearward in a rear lower surface side structure;

FIG. 3 is a rear lower surface structure of the vehicle according to the first embodiment;
It is sectional drawing in the position along middle AA line.

FIG. 4 is a perspective view of a rear under cover main body used for the rear lower surface structure of the vehicle according to the first embodiment.

FIG. 5 is a top view of a rear under cover body used for the rear lower surface side structure of the vehicle according to the first embodiment.

FIG. 6 is a rear view of the rear under cover main body used for the rear lower surface structure of the vehicle according to the first embodiment;

FIG. 7 is a side view of a rear under cover main body used for the rear lower surface structure of the vehicle according to the first embodiment.

FIG. 8 is a schematic diagram illustrating a rear lower surface side structure of a conventional vehicle.

[Explanation of symbols]

3, 4 Front and rear axles 5 Fuel tank 6 Differential gear (drive element) 7 Rear floor panel 7a Storage recess 7b Kick-up portion 7c Front end 14 Vehicle 19 Rear under cover main body 19a Horizontal surface portion 19b Fold line 19c Inclined surface portion 19d Front end edge 19e Rear end Edge 30 Air intake gap 31 Ventilation path 32 Air suction gap (air suction port) 33 Air intake opening

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihito Yamazaki 2 Nissan Motor Co., Ltd. Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor ▲ Taka ▼ Chiaki Yama 2 Nissan Motor, Takara-cho, Kanagawa-ku, Kanagawa Prefecture F-term (for reference) in Jidosha Co., Ltd. 3D003 AA08 BB01 CA13 CA14 DA07 DA08

Claims (6)

[Claims] 1. A rear lower surface structure of a vehicle having a rear under cover main body provided below a drive element positioned behind a fuel tank between axles of the vehicle so as to cover a rear lower surface of the vehicle. The rear under cover main body is spaced apart from the vehicle lower surface side, and at the vehicle front position with respect to the driving element, the front edge of the rear under cover main body is located to form an air intake gap, A ventilation path is provided between the drive element and the rear undercover main body, and a rearwardly inclined surface part forming a part of the ventilation path is provided in the rear undercover main body. A rear lower surface side structure of a vehicle, wherein an air suction port is formed in the rear surface. 2. A rear lower surface structure of a vehicle according to claim 1, wherein said front edge is provided at a position rearward of the vehicle relative to a front end of a kick-up portion of a rear floor panel of said vehicle. 3. The vehicle according to claim 1, wherein the front edge is provided at a height lower than a minimum height above the ground of a rear floor panel of the vehicle. Rear lower side structure. 4. The rear part of a vehicle according to claim 1, wherein a polygonal line forming a front edge of the inclined surface portion is located rearward of the vehicle with respect to the drive element. Lower side structure. 5. A side edge portion of the rear under cover main body,
The rear lower surface side structure of a vehicle according to any one of claims 1 to 4, wherein the mudguard vertical wall is erected upward of the vehicle. 6. An air intake opening for introducing air below the drive element is formed in the rear under cover main body substantially at the center in the vehicle width direction. The rear lower surface side structure of the vehicle according to any one of the preceding claims.