JP3275730B2 - Automobile undercover structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undercover structure which is disposed below a driving unit mounting room such as an engine room of an automobile.

[0002]

2. Description of the Related Art Some automobiles include, for example, Japanese Utility Model Laid-Open No. 4-12.
As shown in Japanese Patent No. 9383, the lower side of the engine room is closed by a flat undercover, and the undercover rectifies the underfloor flow flowing from the front under the engine room to improve aerodynamic characteristics. Known to do so.

[0003] The undercover is formed by bending an upwardly curved portion at the rear end thereof. Even if the rear end of the undercover interferes with an obstacle on the road surface when the vehicle retreats, the warped portion forms an obstacle. The undercover can be prevented from being damaged by riding smoothly.

[0004]

As described above, the rear end of the undercover is formed with an upwardly warped portion, so that the warped portion acts as a flow resistance and causes the engine compartment from the rear end of the undercover. It is undeniable that the outflow property of the internal hot air is deteriorated.

On the other hand, the engine tends to generate a large amount of heat due to its high output and measures against exhaust, and there is a demand for lowering the cooling target water temperature of the radiator in order to improve the engine cooling performance. It is necessary to enhance the outflow of hot air in the room, which requires a high output of the cooling fan, which is disadvantageous in cost.

Therefore, the present invention can avoid damage to the undercover due to road surface interference when the vehicle retreats, and at the same time, does not increase the output power of the cooling fan, so that the hot air in the drive unit mounting room from the rear end of the undercover is removed. It is an object of the present invention to provide an undercover structure for an automobile capable of improving the outflow property of the vehicle.

[0007]

According to a first aspect of the present invention, there is provided a flat under-surface in which a splash guard is formed upright on a lower side of a driving unit mounting room separated from a front portion of a vehicle body and on a side portion on a front wheel side. In the structure that is closed by the cover,
The air dam part is bent downward at the rear end of the under cover, and a slit is formed at the base of the splash guard, which extends forward from the bent base part of the air dam part.

According to a second aspect of the present invention, an easy-bend portion is formed at a position adjacent to the bent base of the air dam portion according to the first aspect so as to extend in the vehicle width direction behind the toe portion where the slit is formed. It is characterized by doing.

According to a third aspect of the present invention, a splash guard is formed by bending a splash guard toward the rear on a side edge of the air dam portion on the front wheel side.

According to a fourth aspect of the present invention, the undercover according to the first to third aspects is divided into right and left parts with a center member disposed in the front-rear direction in a lower central part of the driving unit mounting room as a boundary. An extended portion extending below the center member is formed on the side edge of the air dam portion of the left and right undercover on the vehicle center side, and these extended portions are connected by overlapping in the front-rear direction. .

According to a fifth aspect of the present invention, the undercover according to any one of the first to third aspects has a notch at a central portion on a rear side thereof for receiving a lower portion of the driving unit in the driving unit mounting room. The air dam portion is bent downward at the front edge of the notch portion, and a slit extending forward of the bent base portion of the air dam portion is formed on an extension of the left and right side edges of the notch portion.

According to a sixth aspect of the present invention, the front edge of the notch according to the fifth aspect is located at a position close to the bent base of the air dam portion, and the rear end of the left and right slits is formed across the slits. It is characterized by forming an easily bent portion extending in the vehicle width direction.

[0013]

According to the first aspect of the present invention, the flow rate of the underfloor flow that flows into the underside of the undercover from the front of the vehicle when the vehicle is running is reduced by the air dam portion bent downward at the rear end of the undercover. As a result, a negative pressure having a high negative pressure value is generated near the air dam.

As a result, due to the differential pressure between the high negative pressure generated near the air dam and the internal pressure of the driving unit mounting room, the high-pressure hot air in the driving unit mounting room is displaced by the rear end of the undercover. , The cooling performance of the radiator can be improved without increasing the output of the cooling fan, and the cooling effect of the drive unit and other functional components in the drive unit mounting room can be enhanced. .

[0015] Further, a slit extending forward from the bent base of the air dam portion is formed in the rising formation base portion of the splash guard on the side of the under cover, so that when the vehicle retreats, the air dam portion becomes free from obstacles on the road surface. Even in the case of interference, the slits allow the air dam portion to be freely deformed in the front-rear direction and smoothly pass through obstacles. Damage from the mounting part can be avoided.

According to the second aspect, in addition to the effect of the first aspect, at the position close to the bent base portion of the air dam portion, the easy bending which extends in the vehicle width direction behind the toe portion where the slit is formed is provided. In the case where the air dam portion interferes with obstacles on the road surface when the vehicle retreats, since the air dam portion interferes with the obstacle on the road surface, the bending deformation in the front-rear direction of the air dam portion can be more easily performed by the easy bending portion. As a result, the effect of preventing damage to the undercover can be further enhanced.

According to the third aspect, in addition to the effects of the first and second aspects, since the splash guard is bent and formed rearward on the side edge of the air dam portion on the front wheel side, the splash which is flipped up from the front wheel is provided. Can be prevented from intruding into the driving unit mounting room from the side of the air dam unit and the functional components in the driving unit mounting room being wet.

Further, the strength of the side terminal portion of the air dam portion can be enhanced by the splash guard, and the appearance can be improved by eliminating the side exposure of the side terminal portion.

According to the fourth aspect, in addition to the effects of the first to third aspects, even if the undercover is divided into the left and right undercovers, the air dam portions are provided with the extending portions below the center member. Since the air dam portions are connected via the air dam portion, a sense of continuity between the air dam portions can be obtained and the appearance can be improved.

According to the fifth aspect, in addition to the effects of the first to third aspects, the notch portion for receiving the lower portion of the driving portion provided at the rear center portion of the under cover is formed at the front edge thereof. The air dam section allows the hot air in the driving section mounting room to be positively discharged, and the cooling effect of the driving section mounting room can be enhanced, and the air dam section at the front edge of the notch also has a longitudinal slit by slits on both sides. The bending deformation can be performed freely, and damage to the undercover due to road surface interference when the vehicle retreats can be prevented.

According to the sixth aspect, in addition to the effect of the fifth aspect, in addition to the effect of the fifth aspect, the air dam portion at the front edge of the notch portion is more susceptible to bending deformation in the front-rear direction due to the presence of the easy bending portion against road surface interference when the vehicle retreats. Since it can be performed more easily, the effect of preventing damage to the undercover can be further enhanced.

[0022]

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

FIGS. 1 to 3 show front and rear center members C and M below an engine room E and R as a drive unit installation room like an FF type vehicle (front engine / front drive type vehicle). 1 shows a structure of an undercover used for a vehicle provided with the undercover 1, which is divided into left and right undercovers 1 </ b> A and 1 </ b> B with a center member CM as a boundary.

Each of the left and right undercovers 1A and 1B is formed of a resin material or a steel plate in a flat plate shape, and a splash guard 2 is formed upright on a front wheel side (not shown).

The undercovers 1A and 1B have front sides fixed to the lower surfaces of the first cross members FM via bolts and nuts 3 via mounting holes 1a, and a rear end of the splash guard 2 is connected to a front side (not shown). The rear end portions of the side edges of the vehicle and the center of the vehicle are fastened and fixed to the lower surfaces of the center members C and M through the mounting holes 1a in the same manner as the front side portions. , A range extending from the vicinity of the lower front side of the engine E as a drive unit is closed, and each front edge is fixed to the lower edge of the bumper fascia BF by a clip 4.

An air dam portion 5 is formed at each rear end of the left and right undercovers 1A and 1B by downward bending at an appropriate inclination angle. 5, a slit 6 extending forward from the bent base is formed.

In this embodiment, the left and right undercovers 1
A and 1B are located near the bent bases of the air dams 5 at the forming toe of the slit 6 and the center member C.
An easy bending portion 7 is formed to extend in the vehicle width direction behind the point of attachment to M (the attachment hole 1a).

In the present embodiment, the easily bent portion 7 is formed as a step portion by forming the rear end portion of the air dam portion 5 by bending one step lower than the general portion as a stepped portion. In addition, the bead portion is embossed. You may make it shape | mold.

On the front wheel side of the air dam portion 5, that is, on the side edge near the splash guard 2, a splash guard 8 for preventing splash splashed from the front wheel from scattering inside is formed by bending backward. is there.

Further, extending portions 9 extending below the center members CM are formed at the side edges of the air dam portions 5 and 5 on the vehicle center side. They are polymerized in the directions and connected by screws 10.

According to the structure of the above embodiment, the under-floor flow flowing into the lower side of the undercovers 1A, 1B from the front of the vehicle during running of the vehicle is bent downward at the rear ends of the undercovers 1A, 1B. The flow rate is reduced by the air dam portions 5 and 5 to increase the flow velocity, and a negative pressure having a high negative pressure value is generated near these air dam portions 5 and 5.

As a result, the high-pressure hot air in the engine rooms E and R is generated by the differential pressure between the high negative pressure generated near the air dam portions 5 and 5 and the internal pressure in the engine rooms E and R. As shown by the arrow A in FIG. 2, the undercovers 1A and 1B can be positively discharged from the rear ends thereof, and the radiator RA and the condenser AC for the air conditioner can be used without increasing the output of the cooling fan (not shown). The cooling performance of the cooler can be enhanced, and the cooling effect of the engine E and other functional components in the engine room can be enhanced.

The slits 6, 6 extending forward from the bent bases of the air dams 5, 5 are formed in the bases of the splash guards 2, 2 which rise, so that the air dams 5, 5 are retracted when the vehicle moves backward. , 5 may interfere with obstacles on the road surface, so that the slits 6, 6 allow the air dam portions 5, 5 to freely bend in the front-rear direction to smoothly pass through the obstacles. Can be
Therefore, it is possible to prevent the underdams 1A and 1B from being damaged not only from the damage of the air dam portions 5 and 5 but also from the attachment points of the vehicle body side members such as the center member CM, the front side member or the first cross member FM. Can be avoided.

On the other hand, when the vehicle is running on rainy weather or the like, a splash which is splashed up from a front wheel (not shown) forms undercovers 1A and 1B.
This splash is basically caught by the splash guards 2 and 2 to prevent entry into the engine compartments E and R. Even so, the splash guards 8, 8 are bent and formed rearward on their side edges,
The splash guards 8, 8 prevent splashes from entering the engine rooms E and R from the sides of the air dam portions 5, 5, thereby preventing functional components in the engine room from being wet. .

As described above, by forming the splash guards 8, 8 on the side edges of the air dam portions 5, 5, the strength of the side end portions of the air dam portions 5, 5 can be increased. There is also an advantage that the side terminals of the air dam portions 5 and 5 are not exposed to the side and the appearance can be improved.

Further, in this embodiment, the under cover 1
Are divided into left and right undercovers 1A and 1B, the air dam portions 5 and 5 are formed by the center members CM.
Are connected via the extended portions 9, 9 at the lower side, a sense of continuity of the air dam portions 5, 5 can be obtained when viewed from the lower front side, and the appearance can be improved.

The embodiment shown in FIG. 4 is different from the above-described embodiment in that an under cover used for an FR type vehicle (front engine / rear drive type vehicle) having no center member below the engine room ER is provided. The undercover 1 is a single cover so that the lower side of the engine room ER can be closed from the front end to the portion where the engine E is mounted.
A notch 11 for receiving a lower portion of the engine E is formed in the center of the rear side.

The undercover 1 has a splash guard 2 formed on the left and right sides, a bent air dam section 5 formed on the rear end, and a slit 6 formed on the base of the splash guard 2 where the splash guard 2 rises. The point that the easy bending portion 7 is formed near the bent base portion of the air dam portion 5 and the splash guard 8 is formed by bending the splash guard 8 on the side edge of the air dam portion 5 on the front wheel side are described in the above embodiment. Since the configuration is the same as that of the embodiment, their operation and effect are omitted.

At the front edge of the notch 11, an air dam portion 12 is bent downward at substantially the same inclination angle and protrusion amount as the air dam portion 5.

On the extension of the left and right side edges of the notch 11, a slit 13 is formed which extends forward from the bent base of the air dam 12.

Further, at the position close to the bent base of the air dam portion 12, the easy bending extending in the vehicle width direction across the slits 13, 13 behind the toe of forming the left and right slits 13, 13 at the rear. A step portion as the portion 14 is set.

Accordingly, in this embodiment, the notch 11 provided at the rear central portion of the undercover 1 and receiving the lower portion of the engine E also has the formation portion formed by the air dam portion 12 formed at the front edge thereof. A negative pressure having a high negative pressure value can be generated around it, and the hot air in the engine room ER can be positively discharged from between the air dam portion 12 and the lower front portion of the engine E. , Therefore, engine
The cooling effect in the room E / R can be enhanced.

Also, since the air dam portion 12 can freely bend and deform in the front-rear direction by the slits 13 on both sides, even if the air dam portion 12 interferes with an obstacle on the road surface when the vehicle retreats, the air dam portion is not obstructed. It is possible to prevent the air dam portion 12 and the undercover 1 from being damaged by preventing the air dam portion 12 from passing through the object.
4, the air dam portion 12 can be more easily deformed in the front-rear direction and has an advantage that the effect of preventing the under cover 1 from being damaged can be enhanced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is an explanatory sectional view of the embodiment.

FIG. 3 is an exemplary front perspective view of the vehicle including the under cover according to the embodiment;

FIG. 4 is a perspective view showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Undercover 1A, 1B Left and right undercover 2 Splash guard 5 Air dam part 6 Slit 7 Easy bending part 8 Splash guard of air dam part 9 Extension part 11 Notch part 12 Air dam part of notch front edge 13 Air dam part 12 Both sides of air dam part 12 Slit 14 Easy bending part of air dam part 12 E / R driving unit mounting room E driving unit

Claims (6)

(57) [Claims] 1. A structure in which a lower portion of a drive unit mounting room separated from a front portion of a vehicle body is closed by a flat undercover having a splash guard formed on a side portion of a front wheel so as to rise. An undercover structure for an automobile, wherein an air dam portion is bent downward at a rear end portion of a cover, and a slit extending forward from a bent base portion of the air dam portion is formed in a rising formation base of the splash guard. 2. The air dam portion according to claim 1, wherein an easy-bend portion is formed at a position close to the bent base portion of the air dam portion, the easy-bend portion extending in the vehicle width direction behind the toe of the slit. Automobile undercover structure. 3. The undercover structure for an automobile according to claim 1, wherein a splash guard is bent rearward from a side edge of the air dam portion on a front wheel side. 4. The undercover is formed to be divided into left and right parts with a center member disposed in the front-rear direction at the lower center part of the driving unit mounting room, and the left and right undercovers are provided on the vehicle center side of the air dam part. 4. An extended portion extending below the center member is formed on a side edge of the slab, and these extended portions are overlapped and connected in the front-rear direction.
An undercover structure for an automobile according to any one of the preceding claims. 5. The undercover has a notch in a central portion on the rear side thereof for receiving a lower portion of the driving portion in the driving portion mounting room, and the air dam portion is bent downward at a front edge of the notch. 4. An undercover structure for an automobile according to claim 1, wherein a slit extending forward from a bent base of the air dam portion is formed on an extension of left and right side edges of the cutout portion. . 6. A bendable portion extending in the vehicle width direction across the slits at a position adjacent to the bent base of the air dam portion at the front edge of the notch and behind the left and right slits. The undercover structure according to claim 5, wherein