JP2012086657A - Front structure of motor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further enhance aerodynamic characteristics in a front structure of a motor vehicle including a tire deflector.SOLUTION: The front structure 100 of the motor vehicle includes an engine undercover 2 of a vehicle front part and the tire deflector 3 provided in front of a front wheel 14. The engine undercover 2 has a body part 21 covering a lower part of an engine room 10. An inclined surface 24a extending to a lower side toward a rear side is provided in a front part of the tire deflector 3 on an outer side in a vehicle width direction of the body part 21. The tire deflector 3 is provided to be protruded to an outer side in the vehicle width direction from the inclined surface 24a. A front end part of the inclined surface 24a is positioned on the rear side of a front end part 21b of the body part 21.

Description

  The present invention relates to an automobile front structure including an engine undercover and a tire deflector.

  Conventionally, a technique for improving aerodynamic characteristics of a vehicle has been known, and one of them is provided with a tire deflector as shown in Patent Document 1. The tire deflector is disposed in front of the front wheels, and thereby reduces traveling wind flowing into the tire house. When the traveling wind flows into the tire house, there is a problem that when the traveling wind flows out of the tire house, the flow of the traveling wind of the entire vehicle is disturbed and the CD value (air resistance coefficient) of the vehicle is deteriorated. On the other hand, by providing the tire deflector, the traveling wind flowing into the tire house is reduced and the CD value is improved.

JP-A-10-305784

  However, although the tire deflector can reduce the inflow of the traveling wind to the tire house, the traveling wind collides, resulting in air resistance. That is, in the structure in which the tire deflector is provided, there is room for improvement in aerodynamic characteristics.

  This invention is made | formed in view of this point, The place made into the objective is to further improve aerodynamic characteristics in the front part structure of the motor vehicle provided with the tire deflector.

  The present invention is directed to a front structure of an automobile provided with an engine under cover at the front of the vehicle and a tire deflector provided in front of the front wheels. The engine undercover has a main body portion that covers a lower portion of the engine room, and an inclined surface that extends downward in the rearward direction is located on the outer side in the vehicle width direction of the main body portion and in front of the tire deflector. The tire deflector is provided so as to protrude outward in the vehicle width direction from the inclined surface, and the front end portion of the inclined surface is located behind the front end portion of the main body portion.

  Here, “front” does not mean only the front front in the front-rear direction, but may be in front of the front-rear positional relation regardless of the positional relationship in the vehicle width direction. For example, “in front of the tire deflector” includes not only the front face directly in front of the tire deflector but also an obliquely forward direction from the tire deflector.

  In the case of the above-described configuration, the traveling wind flowing into the lower part of the vehicle body smoothly flows rearward along the lower surface of the main body at the portion corresponding to the main body of the engine under cover. Of the traveling wind, a part of the traveling wind that flows into the region on the outer side in the vehicle width direction from the main body is guided downward by the inclined surface, and the rest hits the tire deflector. In this way, a part of the traveling wind that flows into the region on the outer side in the vehicle width direction from the main body is released downward, so that the amount of air hitting the tire deflector can be reduced.

  Further, by providing the tire deflector so as to protrude outward in the vehicle width direction from the inclined surface, the inclined surface comes close to the main body portion of the engine undercover. Therefore, the traveling wind guided downward by the inclined surface can be easily merged with the traveling wind that originally exists along the main body. That is, it is possible to suppress the disturbance of the flow of traveling wind throughout the vehicle.

  Furthermore, by positioning the front end portion of the inclined surface behind the front end portion of the main body portion, it is possible to prevent the air flow from being separated from the lower surface at the vehicle width direction end portion of the lower surface of the main body portion. . That is, in the configuration without the inclined surface, the air flow in the vehicle width direction end portion of the lower surface is caught in front of the tire deflector and peeled off from the lower surface due to air stagnation in front of the tire deflector. End up. Thereby, CD value will deteriorate. On the other hand, by providing an inclined surface in which the front end portion is positioned behind the front end portion of the main body portion, it is outside in the vehicle width direction from the main body portion, and is a portion inward and in front of the tire deflector in the vehicle width direction. In addition, a downward air flow can be created. In other words, there is a downward air flow due to the inclined surface between the air flow along the lower surface of the main body and the air stagnation in front of the tire deflector, which occurs at the boundary between the main body and the tire deflector. Separation of the obtained air flow can be prevented. Thereby, a smooth flow can be made on the lower surface of the main body, and the CD value can be improved.

  Furthermore, in the configuration in which the inclined surface is provided, the ratio of the traveling wind that escapes downward and the traveling wind directly applied to the tire deflector is adjusted by changing the dimensions of the inclined surface (for example, the length or the width in the vehicle width direction). can do. That is, the CD value can be adjusted according to the size of the inclined surface.

  Moreover, it is preferable that the said inclined surface is adjacent to the said main-body part in the vehicle width direction.

  Also with the above-described configuration, the traveling wind guided downward by the inclined surface can be smoothly merged with the traveling wind that originally exists and flows along the main body.

  Furthermore, it is preferable to further include a side surface connecting the inner end edge in the vehicle width direction of the inclined surface and the outer end edge in the vehicle width direction of the main body portion in front of the inclined surface.

  In the case of the above configuration, it is possible to efficiently increase the traveling wind guided downward by the inclined surface among the traveling wind flowing into the vehicle width direction outside of the main body. Specifically, not only the traveling wind that collides with the inclined surface from the front but also the traveling wind that collides with the side surface from diagonally forward in the vehicle width direction is guided to the inclined surface by the side surface and guided downward by the inclined surface. be able to. That is, it is possible to increase the ratio of the traveling wind guided by the inclined surface in the traveling wind flowing into the region outside the vehicle width direction of the main body.

  Moreover, it is preferable that the lower end part of the said inclined surface is substantially the same height as the lower surface of the said main-body part.

  In the case of the above configuration, the traveling wind guided downward by the inclined surface can be smoothly merged with the traveling wind that originally exists and flows along the main body.

  According to the present invention, by providing the inclined surface, a part of the traveling wind flowing toward the tire deflector can be released downward without hitting the tire deflector, so that the aerodynamic characteristics can be improved.

It is the perspective view which looked at the front left part of the front part structure of a motor vehicle from the lower part. It is a bottom view of the front part structure of a car. It is a side view which shows the front part structure of the left side of a motor vehicle. 2 is a perspective view corresponding to FIG. FIG. 6 is a perspective view corresponding to FIG.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of a front left part of a front structure of an automobile as viewed from below, FIG. 2 is a bottom view of the front structure of the automobile, and FIG. 3 is a side view showing a front structure on the left side of the automobile. The figure is shown. In this specification, unless otherwise specified, “front” means front in the vehicle front-rear direction, and “rear” means rear in the vehicle front-rear direction.

  The front structure 100 of the automobile includes a front bumper 11, front fenders 12 and 12, an engine hood 13 that closes the engine room 10 surrounded by the front bumper 11 and the front fenders 12 and 12, and a front fender 12. The left and right front wheels 14 and 14 located in the tire houses 16 and 16 formed inside the tire houses 16 and 16, the left and right mud guards 15 and 15 that define the front portions of the tire houses 16 and 16, and the engine room 10 An engine under cover 2 that covers from below, left and right tire deflectors 3 and 3 positioned in front of each front wheel 14, and a suspension cross 18 that is connected to the rear end of the engine under cover 2 are provided.

  The engine under cover 2 includes a substantially rectangular main body 21 that covers the lower portion of the engine room 10, and side wall portions 22, 22 that are erected from both ends of the main body 21 in the vehicle width direction. The front part of the main body 21 is gently curved upward. The front end 21 b of the main body 21 is attached to the lower end of the front fender 12. Each side wall 22 includes a first side wall 23, a second side wall 25 located behind the first side wall 23 and outside in the vehicle width direction, a rear end edge of the first side wall 23, and a second edge An inclined wall portion 24 that connects the front end edge of the side wall portion 25 is provided. That is, the side wall part 22 has a step structure. A splash shield 17 is attached to the second side wall portion 25. The splash shield 17 has a function of partitioning the tire house 16 and the engine room 10.

  The mud guard 15 has a substantially triangular horizontal portion 15a and a curved portion 15b extending from the rear end edge of the horizontal portion 15a while being curved upward and rearward. The curved portion 15b is formed in a substantially quarter circle shape in a side view. The mud guards 15 and 15 are adjacent to the right and left sides of the engine under cover 2, respectively. Each mud guard 15 has a front end of the horizontal portion 15 a attached to the lower end of the front fender 12, and an outer edge in the vehicle width direction of the curved portion 15 b is an end edge in the vehicle width direction of the front fender 12 and a front lower end of the front fender 12. Attached to the edge.

  The tire deflector 3 is a member for reducing the amount of running wind flowing into the tire house 16. The tire deflector 3 is a plate-like member bent at approximately 90 °. Specifically, the tire deflector 3 has a substantially rectangular main body 31 and an attachment portion 32 extending from one end edge of the main body 31 and having an angle of about 90 ° with the main body 31. The attachment portion 32 is attached to the rear end portion of the horizontal portion 15 a of the mud guard 15. At this time, the main body 31 hangs downward from the rear end edge of the horizontal portion 15a, and the normal direction thereof faces the vehicle front-rear direction. The tire deflector 3 attached in this way is located outward of the second side wall portion 25 of the engine under cover 2 in the vehicle width direction and in front of the front wheel 14. More specifically, when viewed from the front of the vehicle, the tire deflector 3 has an end on the outer side in the vehicle width direction that overlaps an inner edge in the vehicle width direction of the front wheel 14 and an end on the inner side in the vehicle width direction with the splash shield 17. It overlaps. In other words, the tire deflector 3 is located in front of the vehicle front-rear direction (front side of the vehicle) with respect to a region on the inner side in the vehicle width direction with respect to the front wheel 14 in the tire house 16.

  Next, the inclined wall portion 24 of the engine under cover 2 will be described in detail.

  The inclined wall portion 24 is a flat plate-like member and is inclined so as to extend downward toward the rear. The inner end edge in the vehicle width direction of the inclined wall portion 24 is connected to the rear end edge of the first side wall portion 23, and the outer end edge in the vehicle width direction is connected to the front end edge of the second side wall portion 25. A front end edge (also an upper end edge) of the inclined wall portion 24 is located at the same height as the upper end edge of the first side wall portion 23. A lower end edge (also a rear end edge) of the inclined wall portion 24 is connected to the main body portion 21. Specifically, in the main body 21, a portion near the lower end of the inclined wall portion 24 protrudes outward in the vehicle width direction. A lower end portion of the inclined wall portion 24 is connected to a protruding portion of the main body portion.

  Here, the surface exposed to the vehicle exterior of the inclined wall portion 24 is the inclined surface 24a, the surface exposed to the vehicle exterior of the main body portion 21 is the lower surface 21a, and the surface exposed to the vehicle exterior of the first side wall portion 23 is the first. The side surface 23a and the surface exposed to the vehicle exterior of the second side wall portion 25 are referred to as a second side surface 25a.

  A front end portion (also an upper end portion) of the inclined surface 24 a is located behind the front end portion 21 b of the main body portion 21 of the engine under cover 2. A lower end portion (also a rear end portion) of the inclined surface 24 a is located at substantially the same height as the lower surface 21 a of the main body portion 21. The inclined surface 24a is adjacent to the main body 21, and the inner end edge of the inclined surface 24a in the vehicle width direction is connected to the rear end edge of the first side surface 23a. A lower end edge (also a front end edge) of the first side surface 23 a is connected to an outer end edge in the vehicle width direction of the lower surface 21 a of the main body 21. That is, the inner edge in the vehicle width direction of the inclined surface 24a and the outer edge in the vehicle width direction of the lower surface 21a of the main body 21 are connected via the first side surface 23a. The inclined surface 24a is located on the inner side in the vehicle width direction of the tire deflector 3 when viewed from the front of the vehicle. The first side surface 23a corresponds to a “side surface”.

  Hereinafter, the flow of the traveling wind will be described. When the vehicle moves forward, traveling wind relatively flows from the front of the vehicle toward the rear. And the driving | running | working wind which flows in into the main-body part 21 of the engine undercover 2 among the driving | running winds flowing into the downward direction of a vehicle body flows back along the lower surface 21a. Most of the traveling wind that has flowed into the vehicle width direction outside portion of the main body portion 21 of the engine undercover 2 hits the main body portion 31 of the tire deflector 3 and flows downward from the main body portion 31 or outward in the vehicle width direction. Go. Thereby, the air volume flowing into the tire house 16 is suppressed. Further, a part of the traveling wind that has flowed into the outer side in the vehicle width direction of the main body portion 21 of the engine under cover 2 hits the inclined surface 24a of the inclined wall portion 24 and is guided downward by the inclined surface 24a. It is made to merge with the driving | running | working wind which flows along the lower surface 21a. As a result, not all of the traveling wind that has flowed into the outer portion of the engine under cover 2 in the vehicle width direction than the main body portion 21 collides with the tire deflector 3, but a part of the wind escapes below the main body portion 21. . Although the tire deflector 3 can improve the CD value (air resistance coefficient) by suppressing the inflow of the traveling wind into the tire house 16, the tire deflector 3 has an air resistance because it is a member that the traveling wind collides with. End up. On the other hand, by providing the inclined surface 24 a, a part of the traveling wind that has flowed to the outer side in the vehicle width direction of the main body portion 21 can be merged below the main body portion 21 without being directed toward the tire deflector 3. . Thereby, the CD value can be further improved.

  Next, the results of the wind tunnel experiment will be described in detail. The vehicle having the above-described configuration was used as an example, and two comparative examples in which changes were made were prepared.

  In Comparative Example 1, as shown in FIG. 4, a block 41 that is flush with the lower surface 21a of the main body 21 is provided in front of the inclined surface 24a and outside the first side surface 23a in the vehicle width direction. That is, the comparative example 1 has a configuration in which the main body portion 21 of the embodiment is expanded outward in the vehicle width direction and the side wall of the engine under cover 2 is not a step structure but a flat wall surface.

  In Comparative Example 2, as shown in FIG. 5, a trapezoidal rectangular column 42 having two right-angle corners in cross section is provided in front of the tire deflector 3, and the right-angle corners are a main body portion 31 and an attachment portion 32. It was arranged to match the 90 ° corner formed by A slope 42a (a surface facing a right-angled corner) 42a of the quadrangular column 42 is directed diagonally forward and downward. That is, the comparative example 2 has a configuration in which the inclined surface 24a is substantially enlarged outward in the vehicle width direction and all traveling winds that collide with the tire deflector 3 are guided below the tire deflector 3.

  A wind tunnel experiment (assuming a vehicle speed of 140 km / h) using the examples and comparative examples 1 and 2 thus configured was performed, and the CD value, CLf value, and CLr value were measured. The CLf value is a front-side CL value (air lift coefficient), and the CLr value is a rear-side CL value. Then, the CD value, CLf value, and CLr value of each of the example and the comparative examples 1 and 2 are gently connected to the first side surface 23a and the second side surface 25a, and bulge outward in the vehicle width direction toward the rear ( That is, the CD value, the CLf value, and the CLr value of the configuration having the side wall portion 22 (not having a step structure) were compared. The amount of change is shown in Table 1.

  As can be seen from Table 1, in the example, the CD value is improved by 0.001. In contrast, in Comparative Example 1, the CD value does not change, and the rear CL value is deteriorated by 0.002. In Comparative Example 2, although the CD value was deteriorated by 0.001 and the rear CL value was improved by 0.007, the front CL value was deteriorated by 0.004.

  In Comparative Example 1, the main body 21 is practically enlarged outward in the vehicle width direction. Thus, the CD value is hardly improved by slightly increasing the ratio of the amount of air flowing into the lower part of the main body 21 of the engine under cover 2 and slightly decreasing the ratio of the amount of air colliding with the tire deflector 3. I understand.

  In the second comparative example, the traveling wind that flows into the region outside the main body 21 in the vehicle width direction collides with the inclined surface 42a of the rectangular column 42, is guided by the inclined surface 42a, and flows into the lower side of the rectangular column 42. Since the tire house 16 is positioned behind the quadrangular column 42, some of the traveling wind that flows below the quadrangular column 42 flows into the rear as it is, and flows into the tire house 16 as a front wheel. 14, the air flow in the tire house 16 and the air flow after being discharged from the tire house 16 are disturbed. As a result, it is considered that the CD value deteriorated.

  On the other hand, in the embodiment, a part of the traveling wind that flows into the region on the outer side in the vehicle width direction from the main body 21 can be merged with the flow below the main body 21 by the inclined surface 24a. The amount of air that collides can be reduced.

  Further, in the embodiment, the amount of air that is merged below the main body portion 21 by the inclined surface 24 a out of the traveling wind flowing into the vehicle width direction outside of the main body portion 21 can be increased as compared with the first comparative example. Specifically, in the embodiment, in addition to the traveling wind that collides with the inclined surface 24a from the front, the vehicle collides with the first side surface 23a from the diagonally front on the outer side in the vehicle width direction, and is guided by the first side surface 23a to the inclined surface 24a. The traveling wind that has reached is also merged below the main body 21. In the first comparative example, the main body 21 is simply enlarged outward in the vehicle width direction, and the enlarged portion is not recessed rearward. Therefore, the traveling wind that collided with the side surface of the block 41 from the diagonally front outside in the vehicle width direction Is guided to the tire deflector 3 and collides with the tire deflector 3. That is, even if the amount of protrusion of the inclined surface 24a in the vehicle width direction and the amount of enlargement of the main body portion 21 in the comparative example 1 to the outer side in the vehicle width direction are the same amount, the main body portion 21 flows into the outer side in the vehicle width direction. In the traveling wind, the amount of air released to the lower side of the main body 21 is larger in the embodiment. For this reason, it is considered that the example was able to improve the CD value.

  Furthermore, in an Example, it can prevent that the flow of air peels from this lower surface 21a in the vehicle width direction edge part among the lower surfaces 21a of the main-body part 21. FIG. Specifically, when the inclined surface 24a is not present, the main body 21 and the tire deflector 3 are adjacent to each other in the vehicle width direction. Air stagnation occurs in front of the tire deflector 3. In such a case, the air flowing backward along the vehicle width direction end portion (portion adjacent to the tire deflector 3) of the lower surface 21 a of the main body 21 is caught in the stagnation of the air in front of the tire deflector 3, and the lower surface It is easy to peel from 21a. As a result, the air flow is disturbed along the lower surface 21a, and the CD value may be deteriorated. On the other hand, by providing the inclined surface 24a with the front end located behind the front end 21b of the main body 21, the air flow along the lower surface 21a and the stagnation of air in front of the tire deflector 3 In the meantime, there is an air flow guided downward along the inclined surface 24a. As a result, the air flow along the lower surface 21a can be prevented from being caught in the tire deflector 3 and being separated from the lower surface 21a. Thus, it is considered that the flow along the lower surface 21a can be stabilized and the CD value can be improved.

  Therefore, according to the present embodiment, by providing the inclined surface 24 a on the outer side in the vehicle width direction of the main body 21 and on the inner side in the vehicle width direction of the tire deflector 3 and in front of the tire deflector 3, A part of the traveling wind flowing into the region outside in the vehicle width direction can be guided downward so as not to go to the tire deflector 3. Thereby, the running wind which hits the tire deflector 3 can be reduced.

  In addition, by positioning the inclined surface 24 a on the inner side in the vehicle width direction of the tire deflector 3, that is, at a position close to the main body portion 21, the traveling wind guided downward by the inclined surface 24 a travels on the lower surface 21 a of the main body portion 21. It can be made easier to join the wind.

  In addition, by connecting the inner edge in the vehicle width direction of the inclined surface 24a and the outer edge in the vehicle width direction of the lower surface 21a with the first side surface 23a, the vehicle collides with the first side surface 23a from the diagonally forward side in the vehicle width direction. Since the wind can also escape downward on the inclined surface 24a, the ratio of the travel wind that strikes the tire deflector 3 in the travel wind that flows into the outer portion in the vehicle width direction than the main body portion 21 can be effectively reduced. .

  Further, by positioning the front end portion of the inclined surface 24a behind the front end portion of the main body portion 21, the air flow along the lower surface 21a is caught in the air stagnation in front of the tire deflector 3, and the lower surface 21a. Can be prevented from peeling off. Thereby, the flow along the lower surface 21a can be stabilized.

  Thus, the aerodynamic characteristics can be improved by improving the CD value of the vehicle.

  Further, by setting the lower end portion of the inclined surface 24 a to the same height as the lower surface 21 a of the main body portion 21, the traveling wind guided downward by the inclined surface 24 a can be more easily merged with the traveling air of the lower surface 21 a of the main body portion 21. be able to.

  Furthermore, by making the inclined surface 24a, that is, the inclined wall portion 24 adjacent to the main body portion 21, the above-described inner edge in the vehicle width direction of the inclined surface 24a and the outer edge in the vehicle width direction of the lower surface 21a are connected to the first side surface 23a. And a configuration in which the lower end portion of the inclined surface 24a is set to the same height as the lower surface 21a of the main body portion 21 can be easily realized.

  Furthermore, by changing dimensions such as the width of the inclined surface 24a, it is possible to adjust the proportion of the traveling wind that is directed downward in the traveling wind that flows into the region outside the main body portion 21 in the vehicle width direction.

<< Other Embodiments >>
The present invention may be configured as follows with respect to the embodiment.

  The inclined surface 24a (and the inclined wall portion 24) is formed integrally with the main body portion 21 of the engine under cover 2 and is a part of the engine under cover 2, but is not limited thereto. The inclined surface 24a (and the inclined wall portion 24) may be configured separately from the engine under cover 2. For example, the structure which has arrange | positioned the plate-shaped inclination wall part which has the inclined surface 24a in the 1st side surface 23a of the engine undercover 2 may be sufficient. As long as the inclined wall portion can be disposed at this position, the inclined wall portion may be attached to the engine under cover 2, the mud guard 15, the tire deflector 3, or any An attachment structure can be adopted. Alternatively, the inclined wall portion may be formed integrally with the tire deflector 3. In this case, the inclined wall portion is provided so as to protrude forward from the main body 31 at the inner end in the vehicle width direction of the main body 31 of the tire deflector 3.

  Moreover, although the lower end part of the inclined surface 24a (and inclined wall part 24) is substantially the same height as the lower surface 21a of the main-body part 21, it is not restricted to this. Below the engine under cover 2, there is a large flow of traveling wind along the lower surface 21 a, so that the lower end portion of the inclined surface 24 a (and the inclined wall portion 24) and the lower surface 21 a of the main body portion 21 have substantially the same height. Even if not, the traveling wind guided to the inclined surface 24a easily merges with the traveling wind along the lower surface 21a.

  Further, the tire deflector 3 is positioned on the outer side in the vehicle width direction with respect to the inclined surface 24a, and the inclined surface 24a and the tire deflector 3 do not overlap each other when viewed from the front of the vehicle, but the present invention is not limited to this. That is, as long as the inclined surface 24a is positioned in front of the tire deflector 3, the inclined surface 24a and the inner portion in the vehicle width direction of the tire deflector 3 may overlap each other when viewed from the front of the vehicle.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a front structure of an automobile including an engine undercover and a tire deflector.

DESCRIPTION OF SYMBOLS 100 Front structure 10 of motor vehicle Engine room 14 Front wheel 2 Engine under cover 21 Main-body part 21a Lower surface 21b Front end part 23a 1st side surface (side surface)
24a Inclined surface 3 Tire deflector

Claims (4)

A front structure of an automobile including an engine under cover at the front of the vehicle and a tire deflector provided in front of the front wheels,
The engine under cover has a main body that covers a lower portion of the engine room,
On the outer side in the vehicle width direction of the main body portion and in front of the tire deflector, an inclined surface is provided that extends downward toward the rear,
The tire deflector is provided to protrude outward in the vehicle width direction from the inclined surface,
A front structure of an automobile, wherein a front end portion of the inclined surface is located behind a front end portion of the main body portion. The front structure of an automobile according to claim 1,
The front structure of an automobile, wherein the inclined surface is adjacent to the main body in the vehicle width direction. The front structure of an automobile according to claim 2,
A front structure of an automobile, further comprising a side surface that connects an inner edge in the vehicle width direction of the inclined surface and an outer edge in the vehicle width direction of the main body in front of the inclined surface. In the front structure of the automobile according to any one of claims 1 to 3,
A front structure of an automobile, wherein a lower end portion of the inclined surface is substantially the same height as a lower surface of the main body portion.

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