WO2014129376A1

WO2014129376A1 - Wheel guard for vehicle

Info

Publication number: WO2014129376A1
Application number: PCT/JP2014/053338
Authority: WO
Inventors: アンドレアスクレンヘラー
Original assignee: 日産自動車株式会社
Priority date: 2013-02-19
Filing date: 2014-02-13
Publication date: 2014-08-28
Also published as: GB201302827D0; GB2510898A

Abstract

A wheel guard for a vehicle is disposed as the inner wall of a wheel well. The wheel guard is provided with: a front section which has an opening which permits an air flow between the engine compartment of the vehicle and the wheel well; and a protrusion section which is provided on the front section and which forms a recess connecting to the wheel well. At least one opening is provided in the protrusion section. This wheel guard forms an air flow from the engine compartment to the wheel well, is capable of reducing a swirl in the wheel well, and is capable of improving the aerodynamic properties of the vehicle. Also, the air flow is capable of improving the cooling of the engine.

Description

Vehicle wheel guard

The present invention relates to a wheel guard for vehicles [wheel guard for a vehicle], and more particularly to a vehicle wheel guard that can improve engine cooling, drag acting on the vehicle, and the like.

As fuel costs soar and demand for environmentally friendly vehicles becomes stronger than before, improvements in fuel efficiency have become more desirable. 60% of the force required to drive a vehicle at high speed is used to overcome drag and other aerodynamic effects, so improving aerodynamics (aerodynamic performance) improves fuel economy Contribute directly. For this reason, various techniques for improving the aerodynamics of the vehicle have been proposed.

Aerodynamics is improved by reducing the main aerodynamic forces against vehicle movement such as drag and lift, and increasing the power to move the vehicle. Lift and drag are components of force acting on the movement of an object. Lift is a component of force perpendicular to the approaching flow direction. The drag is a force acting in the direction of the relative flow velocity, and acts in a direction opposite to the vehicle speed in the case of aerodynamics of the vehicle. Drag increases with speed and increases with the differential pressure across the object, so it is highly dependent on the shape of the object.

An object of the present invention is to provide a vehicle wheel guard that optimizes a vehicle shape so as to reduce drag and improve fuel efficiency.

A feature of the present invention is a vehicle wheel guard disposed as an inner wall of a wheel house, comprising at least one opening that allows air flow between the engine compartment of the vehicle and the wheel house. A front portion disposed toward a front end of the vehicle, and a raised portion provided in the front portion that forms a recess communicating with the wheel house, wherein the at least one opening is the A wheel guard is provided that is open to the ridge.

It is a top view of an embodiment of a wheel guard and a front under panel. It is a perspective view which shows the protruding part of the said wheel guard seen from the engine compartment. It is a perspective view which shows the said protruding part seen from the wheel house. It is a top view which shows the said protruding part. It is a perspective view explaining vortex distribution by the conventional wheel guard. It is a side view explaining the pressure distribution by the conventional wheel guard. It is a schematic side view which shows the conventional wheel guard with a vehicle front part. FIG. 5 is a schematic side view showing the wheel guard shown in FIGS. 1 to 4 together with the front portion of the vehicle. FIG. 5 is a perspective view showing a bottom portion of a vehicle including the wheel guard shown in FIGS. 1 to 4;

Hereinafter, an embodiment of a vehicle wheel guard will be described with reference to the drawings. 1 to 3 show the overall arrangement of a wheel guard (also referred to as a wheel house lining and a wheel house inner panel) 10 and an under panel according to the present embodiment. In the present embodiment, the right front portion of the vehicle will be described, but the left front portion also has a similar structure symmetrically.

The wheel guard 10 is a vehicle part that forms a wheel house 11, and partitions the vehicle front part [front end] (engine compartment 23) and the wheel house 11. Its main purpose is to prevent sand, mud, stones and water on the road surface from splashing due to the rotation of the tire.

The radiator is used to lower the temperature of the internal combustion engine. This usually involves passing a liquid (engine coolant) through the engine block to heat the liquid (cooling the engine) and then passing it through a radiator to release the liquid heat to the atmosphere. Done in The liquid is again sent to the engine block and flows through the closed circuit to continue cooling the engine. The position and orientation of the wheel guard 10 of this embodiment will be described with reference to FIG. The wheel guard 10 includes a louver frame 16. The louver frame 16 has an upper louver (upper opening) 18 and a lower louver (lower opening) 19. The wheel guard 10 forms an arch that matches the front wheel of the vehicle. The vehicle also includes a deflector 14 that is disposed in front of the wheel guard 10 and prevents inflow of airflow into the wheel house 11.

The engine compartment 23 is formed between two front wheels. The air flow 90 flows into the front air intake 92 (see FIG. 9), passes through a radiator (not shown), and flows into the engine compartment 23. The radiator is located in front of the engine and just behind the front air intake 92. Due to the air flow flowing in from the front air intake 92, heat dissipation in the radiator is promoted. If the flow rate of air passing through the radiator is increased, the cooling performance is improved.

The louver frame 16 protrudes from the front surface 24 of the wheel guard 10. As shown in FIG. 1, the radius of the inner side 20 of the wheel guard 10 near the engine compartment 23 is smaller than the radius of the outer side 22 of the wheel guard 10 that forms part of the vehicle outer surface. Therefore, the front surface 24 of the wheel guard 10 is a curved surface inclined with respect to the rotating shaft 25 of the wheel. The louver frame 16 is configured along the curved surface of the front surface 24. Hereinafter, the wheel rotation shaft 25 is also referred to as a horizontal axis 25 of the vehicle, and an axis from the front end portion to the rear end portion of the vehicle that is orthogonal to the horizontal axis 25 is referred to as a vertical axis 27.

The deflector 14 is suspended from the bottom surface of the engine compartment 23 immediately before the wheel guard 10 and is arranged in parallel to the horizontal axis 25. Therefore, the deflector 14 is on a tangent line at the forefront portion of the front surface of the louver frame 16. The louver frame 16 has an inner end near the engine compartment 23 and an outer end near the vehicle outer surface. For the aerodynamic purpose described later with reference to FIG. 8, the length of the deflector 14 is made longer than the length of the louver frame 16 along the horizontal axis 25. In the longitudinal direction of the vehicle, the inner end of the deflector 14 is disposed in front of the inner end of the louver frame 16 and is separated from the inner end of the louver frame 16. Further, in the lateral direction of the vehicle, the outer end of the deflector 14 extends several centimeters from the outer end of the louver frame 16 and is brought close to the wheel arch on the outer surface of the vehicle.

2 and 3, the louver frame 16 is formed integrally with the front surface 24 of the wheel guard 10. As shown in FIG. A trapezoidal hollow raised portion 31 is formed on the louver frame 16 on the engine compartment 23 side. The front surface 36 of the raised portion 31 (louver frame 16) is configured along the curved surface of the front surface 24 of the wheel guard 10. The louver frame 16 forms a stair structure having two steps (treads) consisting of an upper step and a lower step. The louver frame 16 includes a lower pedestal [lower base] 32 on the bottom of the engine compartment 23, an upper pedestal [upper base] 34 parallel to the lower pedestal 32, and an upper pedestal 34, a lower pedestal 32, and a front surface 24. Two adjacent trapezoidal end faces 38 are provided. FIG. 3 shows a recess 33 formed on the back side of the hollow raised portion 31 (louver frame 16) of the staircase structure. The recess 33 is formed in the wheel house 11 and communicates with the wheel house 11.

The lower pedestal 32 is larger than the upper pedestal 34 and has a wide trapezoidal shape. The lower pedestal 32 has a front end and a rear end, and the rear end is in contact with the front surface 24 of the wheel guard 10. The upper pedestal 34 is smaller than the lower pedestal 32 and has a wide trapezoidal shape. The upper pedestal 34 also has a front end and a rear end, and the rear end is in contact with the front surface 24 of the wheel guard 10 several centimeters above the lower pedestal 32.

The upper pedestal 34 constitutes the upper part (upper stage) of the staircase structure and includes an upper part of the louver having three openings 40a. As shown in FIG. 4, the openings 40 a are arranged at equal intervals with an intermediate section [intermediate section] 42 (see FIG. 4) interposed therebetween. The three openings 40a are opened in the upper stage (tread surface) of the staircase structure. The front portion of the upper pedestal 34 has a castle-like shape, and forms channels [channels] 44 (see FIG. 2) and ridges [ridges] 46 formed on the front surface 36 of the louver frame 16. is doing. The flow path 44 and the ridge 46 extend substantially vertically. A rectangular protrusion 48 at the front portion of the upper pedestal 34 is formed in front of the intermediate portion 42 that partitions the opening 40a. Each of the rectangular protrusions 48 is provided as a small upper base of the wedge-shaped ridge 46. The inside of the ridge part 46 is hollow, and forms a part of the depression 31 described above on the wheel house 11 side (see FIG. 3). For structural integrity, each front surface of the ridge 46 has the same inclined surface on the surface defined by the front edge of the trapezoidal end surface 38.

For each flow path 44, an upper standing plate [upper riser plate] 50 that forms the rear surface of the flow path 44 is provided between the upper step (tread surface) and the lower step (tread surface) of the staircase structure. Each upper standing plate 50 is parallel to the front surface 24 and is located behind the front end edge of the trapezoid side end surface 38. The depth (in the horizontal direction) of each flow path 44 becomes deeper downward. Each flow path 44 extends only a few centimeters above the lower pedestal 32. That is, the flow path 44 is shorter than the ridge portion 46 (extending to the lower pedestal 32), and the surface of the flow path 44 forms a steeper inclined surface than the ridge portion 46 on the front surface 36.

The lower part of each flow path 44 is provided with a louver lower part having three openings 40b. The three openings 40b are opened on the lower stage (tread surface) of the staircase structure. A lower standing plate 51 is provided between the lower stage (tread) and the bottom of the engine compartment 23 on the front side of each flow path 44.

Accordingly, the louver frame 16 forms a two-tread vent structure that allows communication between the interior of the engine compartment 23 and the interior of the wheel house 11 to allow air flow from the former to the latter. ing. Further, the two-step tread structure forms the above-described staircase structure, and the

openings

40a and 40b for communicating the inside of the engine compartment 23 and the inside of the wheel house 11 are provided at the upper and lower steps (treads) of the staircase structure. ). That is, the

openings

40a and 40b are open horizontally and parallel to each other and vertically upward.

Rotating the wheel creates an air flow that immediately delaminates, and this delaminated air flow creates a large wake behind the wheel. Such wakes (turbulence) and strong vortices that produce large drag and lift will worsen the aerodynamics of the vehicle and consequently fuel consumption. Therefore, the configuration of the wheel and the wheel house 11 is important for the aerodynamics of the vehicle, and the contribution of the wheel to the drag coefficient and the lift coefficient in the entire vehicle is always large. Drag coefficient is a common dimensionless metric that is used to quantify the resistance (drag) of a moving vehicle.

FIG. 5 shows a vortex flow in a wheel house provided with a normal wheel guard 10 '. FIG. 5 shows the wheel sides 52 'and the front lower surface 60' and rear surface 62 'of the wheel guard 10'. A strong vortex is formed not only on the wheel side surfaces 52 'but also on the front lower surface 60' and the rear surface 62 'of the wheel guard 10'. This strong vortex formation is also shown in more detail in FIG. The wheel guard 10 of the present embodiment shown in FIGS. 1 to 4 mainly suppresses the vortex generated on the front lower surface 60 '.

FIG. 6 shows a relative pressure distribution in a wheel house provided with a normal wheel guard 10 '. In the wheel house, the pressure in the vicinity of the wheel guard 10 ′ away from the front lower surface 60 ′ and the rear surface 62 ′ is uniformly slightly higher, and the other vicinity of the wheel guard 10 ′ (that is, the front The pressure in the region near the lower surface 60 'and the rear surface 62') is significantly increased. The local pressure increase at the front lower surface 60 'will be described with reference to FIG.

FIG. 7 shows an engine compartment 23 ′, a wheel rotation shaft 25 ′, and a deflector 14 ′ in addition to a normal wheel guard 10 ′ and the like. As usual, the bottom of the engine compartment 23 'is located below the rotary shaft 25'. The wheel guard 10 'forms a concentric circular arc with the wheel and is in contact with the bottom of the engine compartment 23'. Since the arc center of the wheel arch (that is, the rotation axis 25 ') is located above the bottom surface of the engine compartment 23', the wheel guard 10 'and the engine compartment 23' are connected at an acute angle at a corner 80 '. To do. The shape of the corner portion 80 ′ causes a vortex (see FIG. 5) and a local pressure increase region (see FIG. 6) on the front lower surface 60 ′. Further, the deflector 14 'is also suspended forward by a few centimeters from the corner 80' as usual.

These two characteristics, that is, the distance between the wheel guard 10 'and the deflector 14' and the corner 80 'formed at an acute angle, are arrangements that tend to generate eddy currents [geometry prone to] Stream separation is promoted. The resulting form of air flow in the wheelhouse around the rotating wheel is characterized by unstable and strong vortices that create high pressure regions on the front lower surface 60 'and the rear surface 62'. Therefore, the above two characteristics increase the drag and substantially deteriorate the fuel consumption. The solution of this problem by the wheel guard 10 of the present embodiment shown in FIGS. 1 to 4 will be described with reference to FIG.

As shown in FIG. 8, according to the wheel guard 10 of this embodiment, advantages over the wheel guard 10 'shown in FIG. 7 are obvious. The deflector 14 is suspended at a right angle to the bottom of the engine compartment 23 just before the louver frame 16 (i.e., closer to the wheel house 11) than the conventional deflector 14 'shown in FIG. The airflow is received more efficiently, and the airflow is further deflected away from the wheel house 11.

As shown in FIG. 8, the advantage of the entire staircase structure of the louver frame 16 is easy to understand when viewed from the side. The sharp corner 80 'formed by the conventional wheel guard 10' and the bottom of the engine compartment 23 'is the main factor that generates a vortex on the front lower surface 60' (see FIG. 7). By optimizing the shape of this portion together with the deflector 14, not only the vortex flow is reduced, but also the pressure vibration in the wheel house 11 is reduced, and the vortex flow in the wheel house 11 and the air flow under the floor are reduced. It is also possible to improve the interference. Accordingly, an increase in pressure in the wheel house 11 can be suppressed. As a result of the improvement of the air flow state, the drag coefficient in the entire vehicle is reduced by the wheel guard 10, and aerodynamics and fuel efficiency are improved. When the effect of the wheel guard 10 improved by computer simulation and cavity experiment was measured, the drag coefficient of the entire vehicle was reduced by 0.2%.

In other words, the recess 33 is formed in front of the wheel house 11 by the staircase structure of the louver frame 16 (the front portion of the wheel house 11 is partially expanded), so that the air flow in the wheel house 11 is stagnated. Without underflowing (without increasing pressure). This flow is smoothly caused to flow backward by the air flow deflected by the deflector 14, and the generation of vortex is suppressed.

Another factor contributing to the improved air flow is the streamline 82 shown in FIG. A streamline 82 indicates the airflow flowing from the engine compartment 23 into the wheel house 11 through the

openings

40a and 40b. Due to the pressure reduction in front of the wheel house 11 by the staircase structure of the louver frame 16 and the deflector 14, a low pressure region is formed behind the deflector 14. The air in the engine compartment 23 is normally stagnant and high pressure, but the air flow from the engine compartment 23 (high pressure) to the rear region (low pressure) of the deflector 14 is increased to reduce the pressure in the engine compartment 23. . As a result, the air flow rate passing through the radiator is increased, and the heat dissipation performance of the radiator is improved. The change in cooling airflow passing through the radiator was measured by computer simulation and cavity experiment, and increased by 10.5%.

At this time, since the

openings

40a and 40b are formed horizontally (opened upward), the air flow discharged to the wheel house 11 is directed downward. For this reason, the air flow in the wheel house 11 can be smoothly discharged under the floor. In the present embodiment, since the louver frame 16 has a staircase structure, a front surface 24 and a flow path 44 extending in a substantially vertical direction are formed in the vicinity of the

openings

40a and 40b. For this reason, the airflow is smoothly discharged downward from the

openings

40 a and 40 b to the wheel house 11 along the front surface 24 and the flow path 44. It can be said that the air flow deflected by the deflector 14 is smoothly caused to flow backward by the downward air flow.

The air flow 90 discharged to the wheel house 11 through the louver frame 16 is clearly shown in FIG. The air flow 90 flows into the engine compartment 23 from the front air intake 92 and is discharged to the wheel house 11 through the louver frame 16. In addition to the aerodynamics and engine cooling effect, the staircase structure of the louver frame 16 suppresses mud splash and water splash by the air flow discharged downward from the

openings

40a and 40b, so that road noise and splash Noise [splash noise] is also reduced.

This improvement in aerodynamics and engine cooling is between improved aerodynamics and engine cooling (increased staircase structure and opening size) and structural integrity (smaller opening increases robustness). This is caused by the form of the louver frame 16 determined by the optimal tradeoff. In this embodiment, the total height of the louver frame 16 is about 530 mm, the lengths × widths of the

openings

40a and 40b are about 45 mm × about 15 mm, and the widths of the intermediate portions 42 of the upper base 34 are about 20 mm. The 10.5% increase in cooling air flow and 0.2% decrease in drag coefficient described above were obtained experimentally using the model of the above dimensions.

In this embodiment, in order to improve engine cooling, a wheel guard 10 that allows an air flow between the engine compartment 23 of the vehicle and the wheel house 11 is provided. Since the air in the engine compartment 23 is always stagnant with the air in the wheel house 11 and has a high pressure, the air flow from the engine compartment 23 to the wheel house 11 through the

openings

40a and 40b is increased to increase the pressure. Lower and increase the flow of cooling air through the radiator.

This effect is particularly noticeable when the front pressure of the wheel guard 10 is high when the vehicle is traveling, and the effect of increasing the air flow rate passing through the radiator becomes more pronounced.

When the wheel guard 10 includes a plurality of

openings

40a and 40b that allow an air flow between the engine compartment 23 and the wheel house 11 as in the present embodiment, air from the engine compartment 23 to the wheel house 11 is provided. The flow rate further increases. Therefore, the above-described effect can be obtained more reliably.

The wheel guard 10 of the present embodiment further includes a raised portion 31 that forms a recess 33 communicating with the main volume portion [main volume] of the wheel house 11 at the front portion thereof (that is, the main volume portion has a wheel. Contain). The wheel does not reach the recess and is completely contained within the main volume. The raised portion 31 (that is, the depression 33 on the back side thereof) eliminates the shape in which the eddy current in the front portion of the wheel house 11 is easily formed, and the eddy current is reduced. Further, the raised portion 31 (the depression 33) reduces the pressure vibration in the wheel house 11, and also improves the interference between the vortex flow in the wheel house 11 and the air flow under the floor. Accordingly, an increase in pressure in the wheel house 11 can be suppressed. As a result of the improvement of the air flow state, the drag coefficient in the entire vehicle is reduced by the wheel guard 10, and aerodynamics and fuel efficiency are improved. Typically, due to the separation of the airflow around the wheels, turbulence and eddy currents are generated in the wheel house 11 to increase the drag and deteriorate the drag as a whole vehicle. In the present embodiment, since the raised portion 31 (the depression 33) is formed integrally with the wheel guard 10, the structural strength of the raised portion 31 is improved, and the raised portion 31 is optimal for improving aerodynamics. Can be placed in the area.

In the wheel guard 10 of this embodiment, since at least one opening 40a (40b) is opened in the raised portion 31, the inside of the wheel house 11 having a low pressure from the engine compartment 23 having a high pressure through the opening 40a (40b). (The low pressure in the wheel house 11 also contributes to the formation of the raised portion 31 (the depression 33)). Therefore, the pressure in the engine compartment 23 can be greatly reduced, and the engine cooling effect can be further improved.

In the present embodiment, the raised portion 31 of the wheel guard 10 includes at least one staircase structure having an upper stage and a lower stage, so that road noise can be reduced. Moreover, since the upper stage and the lower stage are horizontal, it is possible to minimize the passage of mud and water from the wheel house 11 through the

openings

40a and 40b.

The entire contents of British Patent Application No. 1302827.9 (filed on Feb. 19, 2013) are hereby incorporated herein by reference. Although the present invention has been described above with reference to embodiments of the present invention, the present invention is not limited to the above-described embodiments. The scope of the invention is determined in light of the claims.

Claims

A vehicle wheel guard arranged as an inner wall of a wheel house,
A front portion disposed toward the front end of the vehicle having at least one opening that allows air flow between the engine compartment of the vehicle and the wheel house;
Forming a recess communicating with the wheel house, and a raised portion provided in the front portion;
The wheel guard, wherein the at least one opening is opened in the raised portion.
The wheel guard according to claim 1,
The wheel guard, wherein the raised portion includes at least one staircase structure having an upper stage and a lower stage.
The wheel guard according to claim 2,
A wheel guard in which the upper stage and the lower stage are horizontal.
The wheel guard according to claim 2 or 3,
The wheel guard, wherein the opening for allowing an air flow between the engine compartment and the wheel house is formed in at least one of the upper stage and the lower stage.
The wheel guard according to claim 4,
The wheel guard, wherein the opening for allowing air flow between the engine compartment and the wheel house is formed in each of the upper stage and the lower stage.
The wheel guard according to any one of claims 2 to 5,
The wheel guard, wherein the raised portion includes at least two of the staircase structures.
The wheel guard according to claim 6,
The wheel guard, wherein the upper stage and the lower stage of each of the two staircase structures form the opening that allows air flow between the engine compartment and the wheel house.
The wheel guard according to claim 6 or 7,
The wheel guard, wherein the upper stage and the lower stage of each of at least two of the staircase structures form the opening that allows air flow between the engine compartment and the wheel house.