Front structure of vehicle

Abstract

This front structure of a vehicle (11) comprises: a dashboard panel (20) that covers a rear part of a power chamber in which a power unit is disposed and a radiator (15) is disposed in a front part; and an undercover (17) that covers a lower part of the power chamber. The undercover (17) has an opening (30) through which the interior and the exterior of the power chamber communicate with each other. The front structure further comprises a cover member (27) that is disposed behind the radiator (15) in the power chamber and covers the rear surface of the radiator (15). The cover member (27) has a rear wall (28), and a pair of side walls (29) facing each other in the vehicle width direction. At least a portion of the opening (30) is surrounded by the rear wall (28) and the pair of side walls (29).

Description

Vehicle front structure

[0001] The present disclosure relates to a front structure of a vehicle.

[0002] Conventionally, this type of vehicle front structure is exemplified by the vehicle body front structure disclosed in Patent Document 1. In such a vehicle body front structure, a radiator is disposed in the front of an engine compartment, and the upper part of the engine compartment is covered by a front hood. An undercover covering the lower part of the engine compartment is provided with an opening that connects the engine compartment to the outside of the vehicle.

[0003] A lower duct is provided on the undercover. A first end opening of the lower duct is connected to the opening, and a second end opening is located adjacent to the bottom of the radiator. Hot air that has passed through the radiator in the engine compartment is guided to the opening by the lower duct and then discharged to the underside of the vehicle body through the opening.

[0004] Japanese Patent Application Laid-Open No. 2006-347385

[0005] In the vehicle body front structure described above, the opening at the second end of the lower duct, which guides air in the engine compartment to the opening in the undercover, is not located directly behind the radiator. Additionally, the opening at the second end of the lower duct faces almost directly upward, not toward the radiator. This makes it difficult for air that has passed through the radiator to flow into the lower duct and thus to be discharged outside the vehicle through the opening. This results in increased air resistance in the engine compartment.

[0006] A vehicle front structure according to one aspect of the present disclosure includes a dash panel covering the rear of a power compartment in which a power unit is disposed and a radiator is disposed at the front, and an undercover covering the lower part of the power compartment. The undercover has an opening that communicates the inside and outside of the power compartment. The front structure further includes a cover member that is disposed behind the radiator in the power compartment and covers the rear surface of the radiator. The cover member has a rear wall and a pair of side walls that face each other in the vehicle width direction. At least a portion of the opening is surrounded by the rear wall and the pair of side walls.

[0007] FIG. 10 is a schematic cross-sectional view of a front part of a vehicle according to an embodiment. FIG. 11 is a perspective view of a cover member in the engine compartment of the vehicle of FIG. 1 as seen from the rear. FIG. 12 is a perspective view showing the positional relationship between the cover member and an opening in the engine compartment of the vehicle of FIG. 1. FIG. 13 is a schematic plan view for explaining the area occupancy rate of the cover portion in the opening of FIG. 3. FIG. 14 is a graph showing the relationship between the area occupancy rate of the cover portion in the opening of FIG. 3 and air resistance in the engine compartment. FIG. 15 is a schematic plan view showing an exposed portion of a modified example. FIG. 16 is a schematic plan view showing an exposed portion of a modified example. FIG. 17 is a schematic plan view showing an exposed portion of a modified example. FIG. 18 is a perspective view showing a use state of the cover member of the modified example. FIG. 19 is a cross-sectional view of FIG. 10.

[0008] Hereinafter, an embodiment will be described with reference to the drawings. In the following description, the front-rear direction, the left-right direction, and the up-down direction correspond to the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction of a vehicle 11, respectively.

[0009] <Front Structure of Vehicle 11> As shown in Fig. 1, an engine room 14, which is an example of a power room, is provided inside the front of the vehicle 11, which runs on tires (not shown) on the ground 12. The engine 13, which is an example of a power unit, is disposed inside the front of the engine room 14. A rectangular plate-shaped radiator 15 is disposed in the front of the engine room 14. The radiator 15 is disposed in an inclined position with respect to the horizontal plane so that its rear end is higher than its front end. For example, the radiator 15 is inclined at approximately 45° with respect to the horizontal plane.

[0010] The upper part of the engine compartment 14 is covered by a front hood 16. The lower part of the engine compartment 14 is covered by an undercover 17. The front part of the engine compartment 14 is covered by a front bumper 19 having a plurality of air vents 18. The rear part of the engine compartment 14 is covered by a dash panel 20.

[0011] A cylindrical guide member 21 is provided between the radiator 15 and the front bumper 19 to guide air that flows from the outside into the engine compartment 14 through each vent 18 in the front bumper 19 to the front surface of the radiator 15. A fan unit 22 is provided on the rear surface of the radiator 15. The fan unit 22 is disposed in an inclined position to match the inclination of the radiator 15. The fan unit 22 has a fan case 23 and a radiator fan 24 that is housed in the fan case 23 and is rotatably driven.

[0012] 1 and 2 , the fan case 23 has a first case portion 25 in the shape of a rectangular box with a bottom, and a cylindrical second case portion 26. The first case portion 25 covers the rear surface of the radiator 15 and houses the radiator fan 24. The second case portion 26 is connected to the center of the bottom wall of the first case portion 25, and the interior of the second case portion 26 communicates with the interior of the first case portion 25. The rear end of the second case portion 26 is covered by a cover member 27. The cover member 27 is disposed behind the radiator 15 in the engine compartment 14 and covers the rear surface of the radiator 15 via the fan case 23.

[0013] <Cover member 27> As shown in Figures 1 to 3, the cover member 27 has a rear wall 28 and a pair of side walls 29 formed integrally with the rear wall 28. The pair of side walls 29 face each other in the left-right direction, which is the vehicle width direction. The rear wall 28 is rectangular when viewed from behind. The side walls 29 are triangular when viewed from the left-right direction. The front and bottom of the cover member 27 are open. The front opening of the cover member 27 is U-shaped. The bottom opening of the cover member 27 is rectangular. The front of the cover member 27 is inclined to match the inclination of the fan device 22.

[0014] The front opening of the cover member 27 covers the rear opening of the second case portion 26. The lower opening of the cover member 27 covers part of the upper surface of the undercover 17. The engine 13 is disposed behind the cover member 27 in the engine compartment 14. That is, the engine 13 is disposed between the cover member 27 and the dash panel 20 in the engine compartment 14.

[0015] 1 to 3, the undercover 17 has an opening 30 that communicates between the inside and outside of the engine compartment 14. The opening 30 has a rectangular shape with its long sides aligned with the left-right direction and its short sides aligned with the front-rear direction. The opening 30 is positioned so as to face the rear end of the lower opening of the cover member 27 in the up-down direction.

[0016] The area of ​​the rear portion of the opening 30 other than both left-right ends is surrounded by the rear wall 28 and the pair of side walls 29 of the cover member 27 in a plan view. That is, the area of ​​the rear portion of the opening 30 other than both left-right ends is covered by the lower part of the cover member 27. The area of ​​the opening 30 that is not surrounded by the rear wall 28 and the pair of side walls 29 of the cover member 27 is an exposed portion 31. That is, the exposed portion 31 is located at both left-right ends of the rear portion of the opening 30. That is, two (or more) exposed portions 31 are located at the rear of the opening 30.

[0017] The area of ​​the opening 30 surrounded by the rear wall 28 and the pair of side walls 29 of the cover member 27 is a cover portion 32. The opening 30 is composed of the cover portion 32 and an exposed portion 31.

[0018] 1 to 3 , when the vehicle 11 is traveling, of the air that flows into the engine compartment 14 from the outside through the air vents 18 of the front bumper 19, the air that passes through the radiator 15 is discharged to the outside of the vehicle through the cover portion 32 of the opening 30. When the vehicle 11 is traveling, of the air that flows into the engine compartment 14 from the outside through the air vents 18 of the front bumper 19, the air that does not pass through the radiator 15 is discharged to the outside of the vehicle through the exposed portion 31 of the opening 30 via the dash panel 20 in the engine compartment 14.

[0019] In this case, the air resistance in the engine compartment 14 changes by changing the area occupancy (size) of the cover portion 32 in the opening 30 (the area indicated by the grid-hatched area in FIG. 4 ) in the direction indicated by the arrow in FIG. 4. FIG. 5 is a graph showing the relationship between the area occupancy of the cover portion 32 in the opening 30 and the air resistance in the engine compartment 14. The dashed line A in FIG. 5 shows the relationship between the area occupancy of the cover portion 32 in the opening 30 and the air resistance in the engine compartment 14 when air flows from the dash panel 20 of the engine compartment 14 to the exposed portion 31 of the opening 30.

[0020] The two-dot chain line B in Fig. 5 shows the relationship between the area occupancy rate of the cover portion 32 at the opening 30 and the air resistance within the engine compartment 14 when air flows from inside the cover member 27 of the engine compartment 14 to the cover portion 32 of the opening 30. The solid line C in Fig. 5 shows the sum of the dashed line A and the two-dot chain line B. It can be seen from the solid line C that the total air resistance within the engine compartment 14 in this example is minimized when the area occupancy rate of the cover portion 32 at the opening 30 is approximately 80%, for example.

[0021] <Operation of the embodiment> Next, a description will be given of the operation when the vehicle 11 is running. As shown in Figure 1, when the vehicle 11 runs on a ground 12 such as a road, air flows from the front of the vehicle 11 through each air vent 18 in the front bumper 19 into the engine compartment 14. Most of the air that flows into the engine compartment 14 is guided by the guide member 21 and passes through the radiator 15, while the remaining air flows toward the dash panel 20 in the engine compartment 14.

[0022] Almost all of the air that has passed through the radiator 15 is guided by the cover member 27 and discharged outside the vehicle through the cover portion 32 at the opening 30. The air discharged outside the vehicle through the cover portion 32 at the opening 30 flows rearward along the underside of the undercover 17. This air flow forms a negative pressure region 33 (the region indicated by dotted hatching in FIG. 1 ) where the air pressure is lower than the surrounding area, near a portion of the underside of the undercover 17 adjacent to the rear side of the opening 30.

[0023] On the other hand, the air that flows into the engine compartment 14 and does not flow to the radiator 15 but flows toward the dash panel 20 in the engine compartment 14 is discharged via the dash panel 20 to the outside of the vehicle through the exposed portion 31 in the opening 30. At this time, because the exposed portion 31 and the negative pressure region 33 are adjacent to each other, the negative pressure region 33 has an effect that promotes the air in the engine compartment 14 to be discharged to the outside of the vehicle through the exposed portion 31 in the opening 30, and also inhibits the outside air from flowing back into the engine compartment 14 from the exposed portion 31.

[0024] In this way, the air that has flowed into the engine compartment 14 is quickly discharged to the outside of the vehicle through the opening 30, thereby suitably reducing air resistance within the engine compartment 14. <Effects of the embodiment> According to the embodiment described above in detail, the following effects are achieved.

[0025] (1) The front structure of the vehicle 11 includes a dash panel 20 that covers the rear of the engine compartment 14, in which the engine 13 is disposed and the radiator 15 is disposed in the front portion, and an undercover 17 that covers the lower portion of the engine compartment 14. The undercover 17 has an opening 30 that communicates between the inside and outside of the engine compartment 14. The front structure of the vehicle 11 further includes a cover member 27 that is disposed behind the radiator 15 in the engine compartment 14 and covers the rear surface of the radiator 15. The cover member 27 has a rear wall 28 and a pair of side walls 29 that face each other in the left-right direction. At least a portion of the opening 30 is surrounded by the rear wall 28 and the pair of side walls 29.

[0026] According to the above-described configuration, almost all of the air that has passed through the radiator 15 is quickly guided by the cover member 27 to the opening 30 and discharged to the outside of the vehicle. This makes it difficult for the air that has passed through the radiator 15 to flow into the engine compartment 14, thereby reducing air resistance within the engine compartment 14.

[0027] (2) In the front structure of the vehicle 11, the opening 30 has an exposed portion 31, which is an area that is not surrounded by the rear wall 28 and the pair of side walls 29. According to the above configuration, air that does not flow through the cover member 27 in the engine compartment 14 can be discharged to the outside of the vehicle through the exposed portion 31.

[0028] (3) In the front structure of the vehicle 11, the exposed portion 31 is disposed at the rear of the opening 30. With the above configuration, air located in the engine compartment 14 closer to the dash panel 20 than the cover member 27 can be discharged to the outside of the vehicle through the exposed portion 31. In this case, a negative pressure region 33 is formed diagonally below and rearward of the exposed portion 31 outside the vehicle due to the flow of air that is guided by the cover member 27 to the opening 30 and discharged to the outside of the vehicle. The influence of this negative pressure region 33 can promote the discharge of air located in the engine compartment 14 closer to the dash panel 20 than the cover member 27 to the outside of the vehicle through the exposed portion 31.

[0029] (4) In the front structure of the vehicle 11, two (or more) exposed portions 31 are arranged at the rear of the opening 30. According to the above configuration, air located closer to the dash panel 20 than the cover member 27 in the engine compartment 14 can be efficiently discharged to the outside of the vehicle through the two (or more) exposed portions 31.

[0030] <Modifications> The above embodiment can be modified as follows: Furthermore, the above embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0031] As shown in FIG. 6 , a plurality of plate-shaped ribs 34 extending in the front-rear direction may be provided at the rear end of the cover member 27. By providing the plurality of ribs 34 so as to be arranged side by side at equal intervals in the left-right direction, a plurality of exposed portions 31 may be formed at the rear of the opening 30, arranged side by side at equal intervals in the left-right direction, in a plan view. In this way, air located closer to the dash panel 20 than the cover member 27 in the engine compartment 14 can be discharged to the outside of the vehicle through the exposed portions 31 in a balanced manner in the left-right direction (vehicle width direction). Note that the arrows in FIG. 6 indicate the air flow. The ribs 34 also contribute to improving the rigidity and heat dissipation of the cover member 27.

[0032] As shown in FIG. 7 , multiple recesses 35 may be provided at the rear end of the cover member 27. By providing multiple recesses 35 so that they are arranged at equal intervals in the left-right direction, multiple exposed portions 31 may be formed at the rear of the opening 30, arranged at equal intervals in the left-right direction, in a plan view. In this way, air located closer to the dash panel 20 than the cover member 27 in the engine compartment 14 can be discharged to the outside of the vehicle through the multiple exposed portions 31 in a balanced manner in the left-right direction (vehicle width direction). Note that the arrows in FIG. 7 indicate the air flow. Furthermore, the recesses 35 (unevenness) can contribute to improving the rigidity and heat dissipation of the cover member 27.

[0033] 6 and 7, the multiple exposed portions 31 do not necessarily have to be arranged side by side at equal intervals in the left-right direction. As shown in Fig. 8, by shortening the length of the cover member 27 in the front-rear direction, a single exposed portion 31 extending in the left-right direction may be formed at the rear of the opening 30.

[0034] As shown in Fig. 9, a plurality of protruding openings 36 may be formed that protrude from the opening 30 rearward beyond the rear end of the cover member 27. The plurality of protruding openings 36 may be formed in the undercover 17 so as to be arranged at equal intervals in the left-right direction. In this case, the protruding openings 36 constitute the exposed portion 31. Furthermore, in this case, the plurality of protruding openings 36 do not necessarily have to be formed in the undercover 17 so as to be arranged at equal intervals in the left-right direction.

[0035] 10 and 11, the radiator 15, the fan unit 22, and the cover member 27 may be arranged in a position perpendicular to the horizontal plane. Even in this case, the same effects as those of the above embodiment can be obtained.

[0036] The exposed portion 31 does not necessarily have to be disposed at the rear of the opening 30. That is, the exposed portion 31 may be disposed, for example, at a side of the front of the opening 30. The exposed portion 31 may be omitted. That is, the opening 30 may be entirely surrounded by the rear wall 28 and the pair of side walls 29 of the cover member 27 in a plan view.

[0037] The vehicle 11 may be an electric vehicle that is driven by an electric motor. In this case, the power unit is configured by the electric motor, and the power room is configured by a motor room in which the electric motor is disposed.

Claims

1. A front structure of a vehicle comprising: a dash panel covering the rear of a power compartment in which a power unit is disposed and a radiator is disposed at the front; and an undercover covering the lower part of the power compartment, wherein the undercover has an opening that connects the inside and outside of the power compartment, and the front structure further comprises a cover member that is disposed behind the radiator in the power compartment and covers the rear surface of the radiator, the cover member having a rear wall and a pair of side walls that face each other in the vehicle width direction, and at least a portion of the opening is surrounded by the rear wall and the pair of side walls.

2. The front structure of a vehicle according to claim 1, wherein the opening has an exposed portion that is an area that is not surrounded by the rear wall and the pair of side walls.

3. The front structure of a vehicle according to claim 2, wherein the exposed portion is disposed at the rear of the opening.

4. The front structure of a vehicle according to claim 3, wherein the exposed portion is one of a plurality of exposed portions, and the plurality of exposed portions are arranged at the rear of the opening.

5. A front structure for a vehicle according to claim 4, wherein the plurality of exposed portions are arranged side by side at equal intervals in the vehicle width direction.

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