Aerodynamic structure for vehicle

Abstract

This aerodynamic structure for a vehicle includes: a roof constituting a vehicle; a spoiler provided at the rear of the roof; and a groove provided in an inclined surface formed at an upper surface rear portion of the spoiler. The groove extends in the vehicle width direction along the rear end of the spoiler.

Description

Aerodynamic structure for vehicles

[0001] The present invention relates to an aerodynamic structure for a vehicle.

[0002] Conventionally, aerodynamic structures for vehicles have been known in which aerodynamic parts such as a spoiler are provided at the rear of a vehicle to apply additional air pressure to the rear of the vehicle, improving stability during high-speed driving and cornering performance, and also reducing air resistance and improving fuel efficiency by adjusting the airflow at the rear of the vehicle.

[0003] In Patent Document 1, there is disclosed an aerodynamic structure for a vehicle wherein a rear edge of a spoiler installed at a rear end of the vehicle is provided with a plurality of protrusions protruding rearward and separated from each other by recesses provided at predetermined intervals in the vehicle width direction, and an upper surface of each protrusion extends coplanarly on a rear end side of an upper surface of the spoiler as a part of the upper surface of the spoiler.

[0004] Japanese Unexamined Patent Publication No. 2017-81487

[0005] The vehicle aerodynamic structure described in Patent Document 1 is intended to reduce the air resistance behind the vehicle by using longitudinal vortices formed behind the protrusions arranged in the vehicle width direction to draw a part of the relatively high-speed airflow into the relatively low-speed airflow below and suppress the strength of lateral vortices generated behind the vehicle. However, in the aerodynamic structure described in Patent Document 1, since a plurality of protrusions protruding rearward are arranged side by side in the vehicle width direction at the rear end of the spoiler, there are problems that processing costs are high and the influence on design is also great.

[0006] The present invention has been made in view of such circumstances, and an object of the present invention is to provide an aerodynamic structure for a vehicle that can reduce air resistance behind the vehicle with a simple and low-cost structure and is also excellent in design.

[0007] The above object of the present invention is achieved by the following configuration. [1] An aerodynamic structure for a vehicle, comprising: a roof constituting the vehicle; a spoiler provided at a rear portion of the roof; and a groove portion provided on an inclined surface formed at a rear portion of an upper surface of the spoiler, wherein the groove portion extends in the vehicle width direction along a rear end portion of the spoiler.

[0008] According to the present invention, a simple and aesthetically pleasing configuration is achieved by providing a groove on the rear upper surface of the spoiler that extends in the vehicle width direction along the rear end of the spoiler, thereby reducing air resistance at the rear of the vehicle.

[0009] Figure 1 is a side view of the main part of the rear of a vehicle to which the aerodynamic rear spoiler structure having the aerodynamic groove structure for vehicles of this embodiment is applied. Figure 2 is a perspective view showing the spoiler. Figure 3 is a plan view showing the spoiler. Figure 4 is an end view of Figure 3 taken along line A-A. Figure 5 is a graph showing the relationship between the drag coefficient CD and the rear wheel lift coefficient CLR with and without the groove. Figure 6(A) shows the airflow behind the vehicle when there is no groove, and Figure 6(B) shows the airflow behind the vehicle when there is a groove. Figure 7(A) shows the air vortex behind the vehicle when there is no groove, and Figure 7(B) shows the generation of air vortices behind the vehicle when there is a groove. Figure 8(A) shows the pressure on the rear of the vehicle when there is no groove, and Figure 8(B) shows the pressure on the rear of the vehicle when there is a groove. Figure 9 is an A-A end view showing the spoiler of the second embodiment.

[0010] Hereinafter, a vehicle aerodynamic structure according to one embodiment of the present invention will be described with reference to the drawings. Furthermore, this embodiment is merely an example of the present invention, and the present invention is not limited to this embodiment. In addition, various modifications or improvements can be made to this embodiment, and such modified or improved forms may also be included in the present invention. The type of vehicle to which the vehicle aerodynamic structure is applied is not limited. For example, it may be an internal combustion engine vehicle (ICEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV).

[0011] In the following drawings, the symbol FR indicates the front of the vehicle, the symbol UP indicates the top of the vehicle, and the symbol LH indicates the left side in the vehicle width direction (left side in the direction of travel). The opposite direction of symbol FR is the rear of the vehicle, the opposite direction of symbol UP is the bottom of the vehicle, and the opposite direction of symbol LH is the right side in the vehicle width direction (right side in the direction of travel). Hereinafter, these directions may simply be referred to as front, rear, top, bottom, left side, and right side.

[0012] (First Embodiment) Figure 1 is a side view of the main part of the rear of a vehicle to which the aerodynamic structure for a vehicle of this embodiment is applied. Figure 2 is a perspective view showing the spoiler. Figure 3 is a plan view showing the spoiler. Figure 4 is an end view taken along line A-A of Figure 3. As shown in Figure 1, the vehicle 10 has a roof panel 11 that covers the upper part of the passenger compartment and the cargo compartment, roof side panels 12 that are arranged on both the left and right sides of the roof panel 11 and extend in the front-rear direction of the vehicle, a vertical rear pillar 13 formed at the rear end of the roof side panel 12, and a tailgate spoiler (hereinafter simply referred to as spoiler) 20 that is detachably attached to the rear ends of the roof panel 11 and the roof side panels 12.

[0013] As shown in Figures 1 to 4, the spoiler 20 has an upper guide portion 21 extending rearward from the rear end of the roof panel 11, a pair of side guide portions 26 extending rearward from the rear ends of a pair of roof side panels 12 and connected to the upper guide portion 21, and a groove portion 30 formed at the rear end of the upper guide portion 21 and extending along the vehicle width direction.

[0014] The upper guide portion 21 is formed to extend rearward along the entire width of the roof panel 11. The upper guide portion 21 has an upper guide front portion 21a that slopes downward toward the rearward direction from the front end, which is smoothly connected to the rear end of the roof panel 11, to the middle portion in the front-rear direction, and an upper guide rear portion 21b that slopes downward toward the rearward direction at an angle of inclination equal to or greater than that of the upper guide front portion 21a.

[0015] The front part 21a of the upper guide is provided with a mounting portion 22 for detachably attaching the front part of the spoiler 20 to the rear end of the roof panel 11. The rear end of the rear part 21b of the upper guide has a pair of curved portions 23, 23 that curve forward as they extend outward in the vehicle width direction, and a groove portion 30.

[0016] As shown in Figure 2 and other figures, the side guide portion 26 extends in the front-rear direction so as to connect the rear end of the roof side panel 12 with both ends in the vehicle width direction of the upper guide portion 21 of the roof panel 11. In this embodiment, the rear end of the side guide portion 26 has a side inclined portion 26a that slopes upward toward the rear and smoothly connects with the vehicle width direction end of the upper guide rear portion 21b.

[0017] The groove 30 is a single groove recessed in the vehicle width direction near the rear of the upper guide rear portion 21b, and is formed over the entire vehicle width direction of the upper guide rear portion 21b. As shown in Figure 4, the groove 30 has a bottom surface 30c recessed in the upper guide rear portion 21b, a front wall portion 30a formed rising from the front end of the bottom surface 30c, and a rear wall portion 30b formed rising from the rear end of the bottom surface 30c, and has a rectangular cross-section. The front wall portion 30a and the rear wall portion 30b have surfaces perpendicular to the inclined surface of the upper guide rear portion 21b.

[0018] As shown in Figure 3, the groove 30 has groove curved portions 31, 31 formed at both ends in the vehicle width direction, which curve along the curved portions 23, 23 at the rear end of the upper guide portion 21. As a result, the width W formed between the rear end of the groove 30 and the rear end of the upper guide portion 21 (rear upper guide portion 21b) in a plan view is kept substantially constant in the vehicle width direction.

[0019] In this embodiment, the width W in the front-to-back direction formed between the rear end of the groove 30 and the rear end of the upper guide portion 21 (rear upper guide portion 21b) in a plan view is set to 10 mm to 50 mm, more preferably to 20 mm to 40 mm.

[0020] (Function and Effects) Next, the function and effects of the spoiler 20 will be explained based on Figures 5 to 9. Figure 5 is a graph showing the relationship between the drag coefficient CD and the rear wheel lift coefficient CLR with and without the groove. Figure 6(A) shows the airflow behind the vehicle when there is no groove, and Figure 6(B) shows the airflow behind the vehicle when there is a groove. Figure 7(A) shows the air vortex behind the vehicle when there is no groove, and Figure 7(B) shows the generation of air vortices behind the vehicle when there is a groove. Figure 8(A) shows the pressure on the rear of the vehicle when there is no groove, and Figure 8(B) shows the pressure on the rear of the vehicle when there is a groove.

[0021] The fluid flow analysis performed using numerical analysis (CDF analysis) was conducted to analyze the airflow separating from the upper surface of the spoiler 20 when the vehicle 10 is in motion, for both cases: when a spoiler 20 without grooves 30 is used and when a spoiler 20 with grooves 30 is used. The analysis results were then compared.

[0022] As shown in Figure 5, it was confirmed that the spoiler 20 with a groove 30 at its rear end reduces both the drag coefficient CD and the rear wheel lift coefficient CLR at the rear end of the vehicle 10 compared to the spoiler 20 without the groove 30.

[0023] As shown in Figure 6, it has been found that a strong vortex is generated behind the vehicle 10 by the airflow separating from the rear end of the spoiler 20. In contrast, it was confirmed that by providing a groove 30 at the rear end of the spoiler 20, the location of the strong vortex generated behind the vehicle 10 is shifted further rearward.

[0024] Specifically, by forming a groove 30 at the rear end of the spoiler 20, airflow flows into the groove, creating a difference in flow velocity between the groove and the upper surface of the roof panel. As a result, as shown in Figure 7, minute vortices are generated in the airflow flowing over the upper surface of the spoiler 20. Therefore, these minute vortices allow the generation location of the strong vortex flow that occurs at the rear of the vehicle to be moved further back. Refer to Figure 6 for this configuration. In Figure 8, darker colors (closer to black) indicate lower pressure, and lighter colors (closer to white) indicate higher pressure. That is, as shown in Figures 6 and 8, the strong vortex flow generated at the rear of the vehicle moves further back from the rear of the vehicle, causing the pressure at the rear of the vehicle 10 to recover (increase). Consequently, the force pulling the vehicle backward at the rear of the vehicle 10 weakens, reducing air resistance and rear wheel lift. As a result, improved fuel efficiency, improved rear wheel grip, and improved steering stability can be expected.

[0025] As described above, the spoiler 20 of this embodiment has a simple and low-cost configuration in which a groove 30 is formed at the rear end of the spoiler 20, extending in the vehicle width direction along the shape of the rear end of the spoiler 20, thereby improving the aerodynamic performance at the rear of the vehicle. Furthermore, by making the groove 30 a single recess having groove curved portions 31 that are curved along the shape of the curved portion 23 at the rear end of the spoiler 20 at both ends in the vehicle width direction, it is possible to improve aerodynamic performance while minimizing the impact of the groove 30 on the appearance of the spoiler 20. In other words, it is possible to achieve both the design and aerodynamic performance of the spoiler 20.

[0026] (Second Embodiment) Next, with reference to Figure 9, a second embodiment of the spoiler 20 will be described in terms of its differences from the example described above. Figure 7 is an A-A end view showing the spoiler of the second embodiment.

[0027] As shown in Figure 9, the groove 40 formed on the rear upper surface of the spoiler 20 may be formed with a V-shaped cross-section instead of the rectangular cross-section of the groove 30. Specifically, the groove 40 in this embodiment has a front wall portion 40a that slopes downward toward the rear from the front end of the groove 40, and a rear wall portion 40b that rises up from the rear end of the front wall portion 40a. With this configuration, the amount of cutout of the groove 40 formed in the spoiler 20 is reduced, making it easier to process and easier to maintain high strength.

[0028] Furthermore, in the above-described embodiment, the groove 30 is formed by a single groove formed in the vehicle width direction at the rear of the spoiler 20 (rear of the upper guide 21b), but it may also be configured as a plurality of discontinuous grooves 30 in the vehicle width direction. Alternatively, a configuration in which a plurality of grooves 30 extending in the vehicle width direction are arranged in the front-rear direction may also be used.

[0029] Furthermore, although the groove 30 described above is attached to the roof panel 11 and formed at the rear end of the tailgate spoiler (roof spoiler) 20, the configuration is not limited to the above. For example, the groove 30 in the vehicle width direction may be formed on a rear spoiler (not shown) provided on the upper surface of a trunk (not shown) formed at the rear of the vehicle.

[0030] It should be noted that the present invention is not limited to the embodiments described above, and can be modified or improved as appropriate.

[0031] As described above, the following matters are disclosed in this specification: (1) an aerodynamic structure for a vehicle comprising: a roof constituting a vehicle; a spoiler provided at the rear of the roof; and a groove provided on an inclined surface formed at the rear of the upper surface of the spoiler, wherein the groove extends in the vehicle width direction along the rear end of the spoiler. With this configuration, the air resistance at the rear of the vehicle can be reduced by a simple and aesthetically pleasing configuration in which a groove is provided on the rear upper surface of the spoiler that extends in the vehicle width direction along the rear end of the spoiler.

[0032] (2) The aerodynamic structure for a vehicle according to (1), wherein the spoiler and the groove have curved portions that curve outward in the vehicle width direction in the vehicle front-rear direction. With this configuration, the design of the spoiler is improved and the position of vortex flow generation by the groove can be shifted in the vehicle width direction.

[0033] (3) The curvature of the curved portion increases toward the front of the vehicle as it moves toward the outside in the vehicle width direction, as described in (2). With this configuration, the design of the spoiler is improved and the position of vortex generation by the groove can be shifted in the vehicle width direction.

[0034] (4) The aerodynamic structure for a vehicle according to any one of (1) to (3), wherein the spoiler has an upper guide portion that extends rearward from the rear end of the roof panel and in which the groove portion is formed, and a pair of side guide portions that extend rearward from the rear ends of the roof rails arranged on both sides of the roof panel in the vehicle width direction and are connected to the upper guide portion. With this configuration, the aerodynamic performance of the spoiler is improved, and the rear end of the roof can be smoothly extended with the spoiler, resulting in a superior design.

[0035] (5) The aerodynamic structure for a vehicle according to (4), wherein the upper guide portion has an upper guide front portion that slopes downward toward the rear from the front end, and an upper guide rear portion that slopes downward toward the rear from the rear end of the upper guide front portion at an angle greater than or equal to the angle of inclination of the upper guide front portion, and the groove portion is formed in the upper guide rear portion. With this configuration, the effect of reducing air resistance by the groove portion becomes more effective.

[0036] (6) A vehicle aerodynamic structure according to any one of (1) to (5), wherein the width in the vehicle longitudinal direction between the groove and the rear end of the spoiler is 10 mm to 50 mm. With this configuration, the effect of reducing air resistance by the groove becomes more effective.

[0037] 10 Vehicle 11 Roof panel (roof) 12 Roof side panel 13 Rear pillar 20 Spoiler, tailgate spoiler 21 Top guide section 21a Front top guide section 21b Rear top guide section 22 Mounting section 23 Curved section 26 Side guide section 26a Side inclined section 30 Groove section 30a Front wall section 30b Rear wall section 30c Bottom surface 31 Groove curved section 40 Groove section 40a Front wall section 40b Rear wall section

Claims

1. A vehicle aerodynamic structure comprising: a roof constituting the vehicle; a spoiler provided at the rear of the roof; and a groove provided on an inclined surface formed at the rear of the upper surface of the spoiler, wherein the groove extends in the vehicle width direction along the rear end of the spoiler.

2. The aerodynamic structure for a vehicle according to claim 1, wherein the spoiler and the groove have curved portions that curve in the vehicle longitudinal direction toward the outside in the vehicle width direction.

3. The curvature of the curved portion increases toward the front of the vehicle as it moves toward the outside in the vehicle width direction, according to claim 2.

4. The aerodynamic structure for a vehicle according to claim 1, wherein the spoiler has an upper guide portion extending rearward from the rear end of the roof panel and having the groove portion formed thereon, and a pair of side guide portions extending rearward from the rear ends of the roof rails arranged on both sides of the roof panel in the vehicle width direction and connected to the upper guide portion.

5. The aerodynamic structure for a vehicle according to claim 4, wherein the upper guide portion has an upper guide front portion that slopes downward toward the rear from the front end, and an upper guide rear portion that slopes downward toward the rear from the rear end of the upper guide front portion at an angle greater than or equal to the angle of inclination of the upper guide front portion, and the groove portion is formed in the upper guide rear portion.

6. The vehicle aerodynamic structure according to any one of claims 1 to 5, wherein the width in the vehicle longitudinal direction between the groove and the rear end of the spoiler is 10 mm to 50 mm.

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