vehicle

Abstract

The present invention provides a vehicle equipped with an underbody cover that can be moved up and down, and which can reduce the loss of kinetic energy by lowering the underbody cover while driving. [Solution] The vehicle comprises a pair of left and right front wheels 11, a front bumper 13, a pair of left and right undercovers 12, and a drive unit. The pair of left and right undercovers 12 are located in the area from near the front end 13b of the front bumper 13 to near the front end 11a of the front wheels 11 in the front-rear direction, spaced apart from each other between the front wheels 11 in the vehicle width direction, and each is provided to cover the bottom surface of the vehicle body. When each of the pair of left and right undercovers 12 is in a lowered and extended state, it has a rear portion (bottom flat portion) 12b in the front-rear direction where the bottom surface 12c is parallel to the road surface.

Description

Technical Field

[0001] The present invention relates to a vehicle, and particularly to a structure of a front lower portion of a vehicle.

Background Art

[0002] Vehicles are required to reduce eddy currents generated during traveling to reduce kinetic energy loss. When a vehicle is traveling, air also flows into the lower side of the vehicle from between the front bumper and the road surface, and eddy currents may be generated below the vehicle to cause kinetic energy loss. Structures intended to suppress the generation of such eddy currents below the vehicle are disclosed in Patent Documents 1 to 3.

[0003] Patent Documents 1 and 2 disclose a vehicle provided with an undercover arranged to extend from a lower portion of the front end of a front bumper to near the rear end of a front wheel. The undercover has a structure in which a front cover portion disposed forward of a front end portion of a wheel house and a rear cover portion disposed rearward of the front end portion of the wheel house are connected to each other. The undercover is connected to an actuator, and is configured to be capable of state change between a stored state where the connection portion between the front cover portion and the rear cover portion is lifted upward, and a deployed state where the connection portion is lowered downward. In the undercover in the deployed state, the front cover portion is inclined such that its height is displaced upward as it goes forward from the connection portion, and the rear cover portion is provided to be inclined such that its height is displaced upward as it goes rearward from the connection portion.

[0004] Patent Document 3 discloses a vehicle including flow regulating members (undercovers) respectively disposed on the left and right sides in the vehicle width direction, and an air actuator that raises / lowers the flow regulating members. Each flow regulating member is disposed in front of each of the left and right front wheels. When the flow regulating members are brought into a lowered state by the air actuator, the lower surface of each flow regulating member is provided with a curved surface whose height is displaced from the upper side to the lower side as it goes from the front to the rear.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-10984 [Patent Document 2] U.S. Patent Application Publication No. 2023 / 0099045 [Patent Document 3] Japanese Patent Publication No. 2007-30549 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the structures disclosed in the above-mentioned Patent Documents 1-3 are considered to have room for improvement in reducing the loss of kinetic energy when the vehicle is in motion. Specifically, when the vehicle is in motion, the air flowing beneath the vehicle also collides with the tire tread at the front end of the front wheel, but in the structures disclosed in Patent Documents 1-3, it is considered that the airflow near the front end of the front wheel becomes stagnant. For this reason, the structures disclosed in Patent Documents 1-3 are considered to have room for improvement in reducing the loss of kinetic energy when the vehicle is in motion by suppressing the stagnation of the airflow near the front end of the front wheel.

[0007] Specifically, in the structures disclosed in the above-mentioned Patent Documents 1-3, when the under cover is deployed, the under cover is positioned such that the gap with the road surface gradually narrows from the front of the vehicle towards the front end of the front wheel, resulting in increased air pressure directly in front of the front wheel. Therefore, in the structures disclosed in the above-mentioned Patent Documents 1-3, it is thought that stagnation occurs in the airflow near the front end of the front wheel during driving. Thus, it is thought that there is room for further improvement in the structures disclosed in the above-mentioned Patent Documents 1-3 to reduce the loss of kinetic energy.

[0008] The present invention aims to solve the above-mentioned problems and provides a vehicle equipped with an under cover that can move up and down, and which can reduce the loss of kinetic energy by lowering the under cover while driving. [Means for solving the problem]

[0009] A vehicle according to one aspect of the present invention comprises a pair of left and right front wheels, a front bumper, a pair of left and right undercovers, and a drive unit. The pair of left and right front wheels are positioned at both ends in the width direction of the vehicle at the front of the vehicle. The front bumper is positioned in front of the pair of left and right front wheels and extends in the width direction at the front end of the vehicle. The pair of left and right undercovers are positioned between the pair of left and right front wheels in the width direction of the vehicle, in the portion extending from near the front end of the front bumper to near the front end of the pair of left and right front wheels in the longitudinal direction of the vehicle, spaced apart from each other in the width direction of the vehicle, and each covers the bottom surface of the vehicle body. The drive unit moves the pair of left and right undercovers up and down.

[0010] In the vehicle according to this embodiment, each of the left and right pair of undercovers, when in the deployed state lowered by the drive unit, has a flat bottom portion in the forward part from the rear edge, where the bottom surface is parallel to the road surface.

[0011] The vehicle according to the above embodiment is equipped with a pair of left and right undercovers, each having a flat bottom surface. The flat bottom surface of each undercover is the part that is parallel to the road surface when in the deployed state. Therefore, in the vehicle according to the above embodiment, when the vehicle is driven with the left and right pair of undercovers deployed, the pressure decreases as it moves towards the rear (rear edge) of the flat bottom surface. Thus, in a vehicle equipped with a pair of left and right undercovers, each having a flat bottom surface, when the vehicle is driven with the left and right pair of undercovers deployed, air hits the front wheels directly in the front-rear direction, suppressing air stagnation in that area and reducing the loss of kinetic energy.

[0012] Furthermore, the vehicle according to the above embodiment does not have an under cover integrally formed in the vehicle width direction, but rather has a left under cover and a right under cover that are spaced apart from each other in the vehicle width direction. For this reason, the increase in vehicle weight and manufacturing cost is suppressed compared to the case in which the vehicle according to the above embodiment has an under cover integrally formed in the vehicle width direction.

[0013] Furthermore, in the above-described vehicle, a pair of left and right undercovers are positioned in the range from near the front end of the front bumper to near the front end of the front wheels in the longitudinal direction, and in the range between the left and right front wheels in the vehicle width direction. As a result of diligent research by the inventors, it has been found that by positioning the pair of left and right undercovers in the above-described range, the airflow that strikes the front end of the front wheels when the vehicle is running in the deployed state can be straightened in the longitudinal direction. The above-described vehicle was made based on this viewpoint, and by positioning the pair of left and right undercovers in the smallest possible range, it is possible to effectively reduce the loss of kinetic energy during driving while suppressing increases in vehicle weight and manufacturing costs.

[0014] Furthermore, since the vehicle according to the above embodiment is equipped with a drive unit that moves a pair of left and right undercovers up and down, it is possible to drive with the undercovers raised without lowering them when driving on roads with large irregularities or when each undercover and its surrounding parts are frozen in a low-temperature environment. Therefore, the vehicle according to the above embodiment can suppress deformation and damage to each undercover and its surrounding parts caused by driving and the up and down movement of the undercovers.

[0015] In the above, "parallel" includes not only cases where the bottom surface of the flat section of each undercover is perfectly parallel to the road surface, but also cases where it is slightly inclined to the road surface (for example, 2 degrees or less). The same applies hereafter.

[0016] In the above embodiment of the vehicle, a powertrain under cover may be further provided, which has a portion that is close to the rear edges of the left and right pair of under covers in the longitudinal direction of the vehicle and extends rearward from the close proximity portion, and covers the area below the vehicle's powertrain for driving. In this case, the powertrain under cover may be positioned such that the bottom surface at the close proximity portion is at approximately the same height as the bottom surface at the rear edges of the left and right pair of under covers when they are in the deployed state.

[0017] The vehicle according to the above embodiment is equipped with a powertrain undercover having a portion adjacent to the rear edge of each undercover, and the adjacent portion on the bottom surface of the powertrain undercover is configured to be at approximately the same height as the bottom surface of the rear edge of each undercover. Therefore, the air passing beneath each undercover is smoothly (without stagnation) guided from the rear edge of the undercover to below the powertrain undercover. Therefore, the vehicle according to the above embodiment is suitable for reducing the loss of kinetic energy when each undercover is deployed.

[0018] In the vehicle according to the above embodiment, the powertrain under cover may have a flat bottom surface in the portion rearward from the aforementioned proximity point.

[0019] The vehicle according to the above embodiment is equipped with a powertrain undercover whose bottom surface is flat, so that the air guided from the rear edges of the left and right undercovers downwards to the powertrain undercover is smoothly (without stagnation) guided to the rear. Therefore, the vehicle according to the above embodiment is even more suitable for reducing the loss of kinetic energy when each undercover is in the deployed state.

[0020] In the vehicle according to the above embodiment, the pair of left and right undercovers may have their respective rear edges arranged in a straight line along the vehicle width direction.

[0021] In the vehicle according to the above aspect, since the rear edge of each undercover is provided in a linear shape along the vehicle width direction, air strikes the front wheels straight in the front-rear direction, which is further suitable for reducing the loss of kinetic energy. That is, when the rear edge of the undercover is oblique to the vehicle width direction, the air that has passed through the rear edge of the undercover is directed obliquely upward, which is disadvantageous for directing air straight to the front end of the front wheel. In order to avoid the above-described problem, the vehicle according to the above aspect is provided with the rear edge of the undercover in a linear shape along the vehicle width direction, so that air can be directed straight to the front end of the front wheel even in the vertical direction. Therefore, the vehicle according to the above aspect is further suitable for reducing the loss of kinetic energy.

[0022] In the vehicle according to the above aspect, when assuming a vehicle central axis that passes through the center in the vehicle width direction and extends in the front-rear direction of the vehicle, the pair of left and right undercovers may be arranged symmetrically to each other with respect to the vehicle central axis, and may have shapes that are symmetrical to each other left and right.

[0023] In the vehicle according to the above aspect, since the left and right undercovers are provided in a bilaterally symmetrical arrangement and shape with respect to the vehicle central axis, the air that has flowed into the lower part of the vehicle from the front can be made into a symmetrical flow in the vehicle width direction. Therefore, the vehicle according to the above aspect is suitable for reducing the loss of kinetic energy while ensuring steering stability during traveling.

[0024] The vehicle according to the above aspect may further include an outside air temperature measurement unit, a vehicle speed measurement unit, and a control unit. The outside air temperature measurement unit measures the outside air temperature. The vehicle speed measurement unit measures the traveling speed of the vehicle. The control unit acquires outside air temperature information from the outside air temperature measurement unit and vehicle speed information from the vehicle speed measurement unit, and issues a command to the drive unit to raise or lower the pair of left and right undercovers based on the two acquired pieces of information.

[0025] In the vehicle according to the above aspect, the control unit acquires outside air temperature information and vehicle speed information, and issues an ascending / descending command to the drive unit based on the acquired information (vehicle information). Therefore, when the outside air temperature is low and freezing of the road surface or freezing of the mechanisms of each undercover and its peripheral portions is a concern, the pair of left and right undercovers are not caused to descend even when the vehicle speed is high. In addition, when the vehicle speed is low, it is presumed that the vehicle is traveling in an urban area or the like, so each undercover is not caused to descend. As a result, in the vehicle according to the above aspect, when the outside air temperature is relatively low or the vehicle speed is relatively low, each undercover is raised to suppress deformation and damage of each undercover and its peripheral portions.

[0026] On the other hand, in the vehicle according to the above aspect, when it is determined that the outside air temperature is relatively high and the vehicle speed is relatively high, the pair of left and right undercovers are caused to descend because freezing or urban area traveling as described above is not assumed. As a result, the generation of eddy currents near the front end of the front wheels can be suppressed, and the loss of kinetic energy can be reduced. Effects of the Invention

[0027] The vehicle according to each of the above aspects can suppress deformation and damage of the undercover and its peripheral portions during traveling by raising the undercover, and can suppress the generation of stagnation of air flow near the front end of the front wheels by lowering the undercover, thereby reducing the loss of kinetic energy. Brief Description of the Drawings

[0028] [Figure 1] It is a perspective view showing the front lower part of the vehicle according to the embodiment. [Figure 2] It is a bottom view showing the front lower part of a vehicle. [Figure 3] It is a schematic diagram showing a structure related to the movement of the undercover. [Figure 4] (a) is a side view showing the deployed state where the undercover is lowered, and (b) is a side view showing the retracted state where the undercover is raised. [Figure 5] This is a side view illustrating the placement and shape of the underbody cover. [Figure 6] This is a bottom view showing the underbody. [Figure 7] This is a bottom view showing the undercover of the comparative example. [Figure 8] This is a cross-sectional view showing the positional relationship between the under cover and the PT cover when they are in the deployed state. [Figure 9] This is a cross-sectional view showing the positional relationship between the under cover and the PT cover when the under cover of the vehicle in the comparative example is in the deployed state. [Figure 10] This is a block diagram showing the control configuration related to the movement of the underbody cover. [Figure 11] This diagram shows the reference maps that are pre-stored in the reference map storage unit of the control unit. [Figure 12] This is a flowchart illustrating the movement control of the underbody cover performed by the control unit. [Figure 13] (a) is a schematic diagram showing the under cover in the deployed state in a vehicle according to the embodiment, (b) is a graph showing the pressure change in the longitudinal direction under the under cover, and (c) is a schematic diagram for explaining the airflow at the front underside of the vehicle. [Figure 14] (a) is a schematic diagram showing the under cover in the deployed state of a vehicle relating to the comparative example, (b) is a graph showing the pressure change in the longitudinal direction under the under cover, and (c) is a schematic diagram to explain the airflow at the front underside of the vehicle. [Modes for carrying out the invention]

[0029] Embodiments of the present invention will be described below with reference to the drawings. The embodiments described below are illustrative examples of the present invention, and the present invention is not limited to these embodiments except for its essential configuration.

[0030] Furthermore, in the diagrams used in the following explanation, "FR" indicates the front of the vehicle, "RR" indicates the rear of the vehicle, "LH" indicates the left side of the vehicle, "RH" indicates the right side of the vehicle, "UP" indicates the top of the vehicle, and "LO" indicates the bottom of the vehicle.

[0031] 1. Structure of the front lower part of vehicle 1 The structure of the front lower part of vehicle 1 according to this embodiment will be explained with reference to Figures 1 to 3.

[0032] As shown in Figure 1, the vehicle 1 is equipped with a pair of front wheels 11 (left front wheel 11L, right front wheel 11R), a pair of undercovers (left undercover 12L, right undercover 12R), a front bumper 13, a pair of deflectors 14 (left deflector 14L, right deflector 14R), and a powertrain undercover (PT cover) 15 at the front lower part.

[0033] As shown in Figures 1 and 2, the left front wheel 11L is located in the left wheel well 1aL, and the right front wheel 11R is located in the right wheel well 1aR. That is, the pair of left and right front wheels 11 are located at both ends in the width direction of the vehicle at the front of the vehicle 1.

[0034] The left under cover 12L and the right under cover 12R are located in the area between the left and right front wheels 11 in the vehicle width direction, extending from the vicinity of the front end 13b of the front bumper 13 to the vicinity of the front ends 11a of the pair of front wheels 11 in the front-rear direction. The left under cover 12L and the right under cover 12R are spaced apart in the vehicle width direction, with a gap D between them, and each is provided to cover a part of the bottom surface of the vehicle body.

[0035] As shown in Figure 2, we assume a virtual axis (vehicle central axis) Ax1 that passes through the center of the vehicle width direction in vehicle 1 and extends in the longitudinal direction. In this case, the left under cover 12L and the right under cover 12R are arranged symmetrically with respect to the vehicle central axis Ax1 and have symmetrical shapes. The width W of the left under cover 12L in the vehicle width direction and the width W of the right under cover 12R in the vehicle width direction are the same. In this embodiment, as an example, a pair of left and right under covers 12 are provided such that the width W is 300 mm or more. In this embodiment, the pair of left and right under covers 12 are formed using a resin material (as an example, PP: polypropylene).

[0036] The front bumper 13 is positioned in front of the pair of front wheels 11 and extends in the width direction at the front end of the vehicle 1.

[0037] The left deflector 14L is located directly in front of the left front wheel 11L and is positioned close to the left side (outer side in the vehicle width direction) of the left under cover 12L. The right deflector 14R is located directly in front of the right front wheel 11R and is positioned close to the right side (outer side in the vehicle width direction) of the right under cover 12R.

[0038] The PT cover 15 is positioned close to the rear edges 12d of the pair of left and right undercovers 12 in the front-rear direction, and has a portion that extends from the point of proximity to the rear. The PT cover 15 is positioned to cover the area below the powertrain (not shown) for driving, which is mounted in the powertrain room at the front of the vehicle 1. The powertrain of the vehicle 1 is not particularly limited, but could be, for example, an engine or a drive motor.

[0039] As shown in Figure 2, the PT cover 15 is positioned to avoid the wheel wells 1aL and 1aR.

[0040] As shown in Figure 3, the vehicle 1 includes an actuator 17 and a link mechanism 16 that connects the actuator 17 to the under cover 12. Although Figure 3 shows one of the left and right under covers 12, and the link mechanism 16 and actuator 17 connected to that under cover 12, in the vehicle 1 according to this embodiment, the link mechanism 16 and actuator 17 are provided corresponding to the left and right under covers 12L and 12R, respectively.

[0041] In this embodiment, the actuator 17 and the link mechanism 16 constitute a drive unit that moves the under cover 12 up and down. The actuator 17 is fixed to the perimeter frame 18 as an example. Therefore, the under cover 12 is configured to move up and down relative to the perimeter frame 18 by the drive of the actuator 17, as shown by arrow A.

[0042] 2. Up and down movement of undercover 12 Each of the left and right undercovers 12 is configured to be able to move up and down by a drive unit including an actuator 17, as described above. In the vehicle 1 according to this embodiment, the left and right undercovers 12 are configured to be able to change between an deployed state in which both are lowered and a retracted state in which both are raised. The deployed state and the retracted state of the undercovers 12 will be explained with reference to Figure 4. Note that Figure 4 shows only one of the left and right undercovers 12, but the other undercover 12 is also configured to move up and down synchronously.

[0043] As indicated by arrow B1 in Figure 4(a), the pair of left and right undercovers 12 can assume a position where they protrude below the lower edge 13a of the front bumper 13 (deployed state).

[0044] On the other hand, as shown by arrow B2 in Figure 4(b), the left and right pair of undercovers 12 can be positioned in a way that at least a portion of them is stored inside the front bumper 13 (stored state). In this embodiment, one example is a configuration in which a portion of each of the left and right pair of undercovers 12 protrudes below the lower edge 13a of the front bumper 13 in the stored state, but a configuration in which the entirety of each of the left and right pair of undercovers 12 rises above the lower edge 13a of the front bumper 13 may also be adopted.

[0045] 3. Detailed structure of each of the left and right undercovers 12 The detailed structure of each of the left and right undercovers 12 will be explained using Figures 5 to 7. Figure 5 is a side view of one of the left and right undercovers 12, and Figure 6 is a bottom view of one of the undercovers 12 (left undercover 12L) viewed from below. Figure 7 is a bottom view of the undercover 92 of a vehicle related to a comparative example, viewed from below.

[0046] As shown in Figure 5, the under cover 12 is provided such that the front portion 12a and the rear portion 12b are smoothly continuous in the front-rear direction. The rear portion 12b of the under cover 12 is a continuous portion from the connection point with the front portion 12a to the rear edge portion 12d, and has a bottom surface 12c that is parallel to the road surface when deployed. That is, the rear portion 12b of the under cover 12 is a bottom flat portion configured such that the bottom surface 12c becomes a plane (flat) parallel to the road surface when deployed.

[0047] In the above, "parallel" includes not only cases where the bottom surface 12c of the bottom flat portion (rear part) 12b of the under cover 12 is perfectly parallel to the road surface, but also cases where it is slightly inclined to the road surface at an angle (for example, 2 degrees or less). The same applies hereafter.

[0048] The front portion 12a of the under cover 12 is smoothly continuous with the rear portion 12b, and is composed of a smooth curved surface such that the bottom surface 12c is gradually displaced upward as it moves from the connection point with the rear portion 12b towards the vicinity of the front end 13b of the front bumper 13. The front portion 12a is provided with, for example, a radius of curvature R1. In this embodiment, the radius of curvature R1 is, for example, 30 mm to 70 mm.

[0049] In the deployed state, the under cover 12 is positioned such that the front end of its front portion 12a is located behind the front end 13b of the front bumper 13 by a dimension G. In this embodiment, dimension G is, for example, 70 mm to 90 mm.

[0050] As shown in Figure 6, when the under cover 12 is viewed from below, the under cover 12 has an outer edge portion 12g that defines the outside in the vehicle width direction and an inner edge portion 12f that defines the inside. The under cover 12 also has a front edge portion 12e that defines the front side of the front portion 12a and a rear edge portion 12d that defines the rear side of the rear portion 12b.

[0051] The outer edge 12g and inner edge 12f of the under cover 12 are positioned approximately parallel to the vehicle's central axis Ax1 (see Figure 2). The rear edge 12d of the under cover 12 is provided in a straight shape along the vehicle's width direction. The rear edge 12d is positioned in front of the wheel well 1a, and is positioned to avoid the wheel well 1a.

[0052] Assuming a virtual line L0 along the vehicle width direction, the front edge portion 12e of the under cover 12 has an inclined surface on the inward side in the vehicle width direction that is inclined at an angle θ1 with respect to the virtual line L0 and extends further forward towards the inner edge portion 12f.

[0053] The effects of the undercover 12 configured as described above will be explained by comparing it with the comparative example undercover 92 shown in Figure 7.

[0054] First, as shown in Figure 7, the comparative example under cover 92 has an inclined surface on the inside in the vehicle width direction at the front edge portion 92e defining the front side of the front portion 92a, which is inclined at an angle θ9 with respect to the imaginary line L0 and extends further rearward towards the inner edge portion 92f. In addition, the comparative example under cover 92 has a rear edge portion 92d defining the rear side of the rear portion 92b, which is composed of an inclined surface that extends further rearward from the outer edge portion 92g towards the inner edge portion 92f.

[0055] In the comparative example undercover 92 shown in Figure 7, the airflow FL91 that flows over the inclined surface of the leading edge 92e and down the undercover 92 flows diagonally outward, intersecting the inclined surface, and flows rearward along the bottom surface of the rear 92b. Then, the airflow FL91 that flows rearward along the bottom surface of the rear 92b passes through the trailing edge 92d and flows diagonally outward.

[0056] In the comparative example undercover 92, a portion of the airflow FL91 that passes through the trailing edge 92d and flows diagonally outward, and the airflow FL92 that flows rearward along the outer edge 92g, collide in the region indicated by arrow C. As a result, the air pressure in this region increases, and the airflow is deflected diagonally upward. Therefore, in a vehicle equipped with the comparative example undercover 92, the airflow hits the front end of the front wheel (tire tread) in a diagonal direction in the vertical direction, and it is considered that the effect of reducing kinetic energy loss is small.

[0057] In contrast, as shown in Figure 6, in the under cover 12 of this embodiment, the air that flows over the inclined surface of the leading edge 12e of the under cover 12 and flows downward towards the inner edge 12f in an oblique inward direction that intersects with the inclined surface (flow FL2). Then, the airflow FL2 that reaches the inner edge 12f changes its direction of flow along the inner edge 12f and flows rearward along the vehicle's central axis Ax1 (see Figure 2).

[0058] Furthermore, since the under cover 12 of this embodiment has a rear edge portion 12d that is formed in a straight shape along the vehicle width direction, the air that flows backward below the rear portion 12b of the under cover 12 flows backward along the vehicle's central axis Ax1 (see Figure 2) (flow FL1). For this reason, in the under cover 12 of this embodiment, collision between a portion of the airflow FL1 and the airflow FL3 that flows backward along the outer edge portion 12g can be suppressed, and the deflection of the airflow diagonally upward can also be suppressed.

[0059] Therefore, in the vehicle 1 according to this embodiment, the air flowing from front to rear between the under cover 12 and the road surface can be prevented from colliding with the front end (tire tread) 11a of the front wheel 11 at an oblique angle in either the width direction or the vertical direction, making it suitable for reducing the loss of kinetic energy.

[0060] In the vehicle 1 according to this embodiment, the inclination angle θ1 of the inclined surface of the leading edge portion 12e of the under cover 12 is 0deg to 10deg (for example, 5deg).

[0061] 4. Arrangement configuration of the under cover 12 in the vertical direction In this embodiment, the under cover 12 has a defined vertical position in the deployed state, taking into consideration its positional relationship with the PT cover 15. The vertical arrangement of the under cover 12 will be explained using Figures 8 and 9. Figure 8 is a cross-sectional view showing the positional relationship between the under cover 12 and the PT cover 15 in this embodiment. Figure 9 is a cross-sectional view showing the positional relationship between the under cover 92 and the PT cover 95 of a comparative example.

[0062] As shown in Figure 8, the PT cover 15 has a portion (proximity portion) 15b immediately behind the rear edge portion 12d of the unfolded under cover 12, which is close to the rear edge portion 12d. The portion 15c of the PT cover 15 that extends rearward from the proximity portion 15b has a flat bottom surface 15a.

[0063] Furthermore, when the under cover 12 is in the deployed state, liquid-tightness and airtightness are ensured by sandwiching a sealing member 19 between it and the front bumper 13.

[0064] As shown in Figure 8, the vertical position of the under cover 12 in the deployed state is set such that the bottom surface 12c of the rear edge 12d of the under cover 12 and the bottom surface 15a of the adjacent area 15b of the PT cover 15 are at approximately the same height. Therefore, the air passing beneath each under cover 12 is smoothly (without stagnation) guided from the rear edge 12d of the under cover 12 to the area below the PT cover 15. Thus, the vehicle 1 is suitable for reducing the loss of kinetic energy when each under cover 12 is deployed.

[0065] Furthermore, since the bottom surface 15a of the portion 15c of the PT cover 15 is flat, the air guided from the rear edge 12d of each under cover 12 to the bottom of the PT cover 15 is smoothly (without stagnation) guided to the rear. Therefore, the vehicle 1 is even more suitable for reducing the loss of kinetic energy when each under cover 12 is in the deployed state.

[0066] On the other hand, as shown in Figure 9, in the comparative example, the under cover 92 is set such that, when deployed, the vertical position of the under cover 92 is such that the bottom surface 92c of the rear edge 92d of the under cover 92 and the bottom surface 95a of the adjacent area 95b of the PT cover 95 are at different heights (a height difference occurs between them). Therefore, when air passing beneath the under cover 92 of the comparative example flows from the rear edge 92d of the under cover 92 to the bottom of the PT cover 95, it is thought that the airflow becomes stagnant at the point indicated by arrow E. Thus, in a vehicle equipped with the under cover 92 of the comparative example, it is thought that the loss of kinetic energy cannot be sufficiently reduced even when the under cover 92 is deployed.

[0067] 5. Control configuration for the movement of the under cover 12 The control configuration related to the movement (up and down movement) of the under cover 12 will be explained using Figures 10 and 11.

[0068] As shown in Figure 10, the vehicle 1 further comprises an outside temperature measurement unit 20, a vehicle speed measurement unit 21, and a control unit 22. The outside temperature measurement unit 20 measures the outside temperature around the vehicle 1 and inputs the measured outside temperature information to the control unit 22.

[0069] The vehicle speed measurement unit 21 measures the driving speed (vehicle speed) of the vehicle 1 while it is in motion and inputs the measured vehicle speed information to the control unit 22.

[0070] The control unit 22 is configured with a microprocessor including an MPU / CPU, ASIC, ROM, RAM, etc., and memory. The control unit 22 executes firmware pre-stored in memory to acquire outside temperature information and vehicle speed information as vehicle information and performs drive control of the actuators 17 (left actuator 17L, right actuator 17R).

[0071] The control unit 22 includes a reference map storage unit 221, a cover state determination unit 222, and an actuator drive command unit 223. The reference map storage unit 221 pre-stores a reference map in which an outside temperature threshold and a vehicle speed threshold are defined as thresholds for raising / lowering the under cover 12.

[0072] As shown in Figure 11, the reference map stored in the reference map storage unit 221 defines an ambient temperature threshold Ts, which is the ambient temperature threshold for raising or lowering the undercover 12 (left undercover 12L, right undercover 12R), and a vehicle speed threshold Vs, which is the vehicle speed threshold. The ambient temperature threshold Ts and the vehicle speed threshold Vs may differ depending on the destination of the vehicle 1. In this embodiment, as an example, the ambient temperature threshold Ts is defined to be in the range of 5°C to 7°C, and the vehicle speed threshold Vs is defined to be in the range of 45 km / h to 60 km / h.

[0073] The cover state determination unit 222 determines whether the under cover 12 should be in the deployed state (lowered state) or the retracted state (upward state) based on the acquired outside temperature information and vehicle speed information, and the reference map stored in the reference map storage unit 221.

[0074] Based on the results determined by the cover state determination unit 222, the actuator drive command unit 223 issues drive commands to the left actuator 17L and the right actuator 17R in a synchronized manner.

[0075] 6. Drive control of actuator 17 performed by control unit 22 The method for controlling the drive of the actuator 17, which is performed by the control unit 22, will be explained using Figure 12.

[0076] As shown in Figure 12, the control unit 22 determines whether the outside temperature T is lower than the outside temperature threshold Ts defined in the reference map (see Figure 11) based on the outside temperature information obtained from the outside temperature measurement unit 20 (step S1). If the control unit 22 determines that the outside temperature T is lower than the outside temperature threshold Ts (step S1: Yes), the cover state determination unit 222 decides to put the left under cover 12L and the right under cover 12R into the retracted state, and the actuator drive command unit 223 issues an upward command to the left actuator 17L and the right actuator 17R (step S3).

[0077] On the other hand, if the control unit 22 determines that the outside temperature T is the same as or higher than the outside temperature threshold Ts (step S1: NO), it determines, based on the vehicle speed information obtained from the vehicle speed measurement unit 21, whether the vehicle speed V is lower than the vehicle speed threshold Vs defined in the reference map (see Figure 11) (step S2). If the control unit 22 determines that the vehicle speed V is lower than the vehicle speed threshold Vs (step S2: YES), the cover state determination unit 222 decides to put the left under cover 12L and the right under cover 12R into the retracted state, and the actuator drive command unit 223 issues an upward command to the left actuator 17L and the right actuator 17R (step S3).

[0078] In response, if the control unit 22 determines that the vehicle speed V is equal to or higher than the vehicle speed threshold Vs (step S2: NO), the cover state determination unit 222 determines that the left under cover 12L and the right under cover 12R should be deployed, and the actuator drive command unit 223 issues a lowering command to the left actuator 17L and the right actuator 17R (step S4). That is, in the vehicle 1 according to this embodiment, if the control unit 22 determines that the outside temperature T is equal to or higher than the outside temperature threshold Ts, and the vehicle speed V is equal to or higher than the vehicle speed threshold Vs, it issues a command to the drive unit including the left actuator 17L and the right actuator 17R to lower the left under cover 12L and the right under cover 12R in synchronous motion.

[0079] The control unit 22 repeatedly executes steps S1 to S4 when the vehicle 1 is in the ignition state.

[0080] 7. Effects Vehicle 1 according to this embodiment is equipped with a pair of left and right undercovers 12, each having a rear portion 12b which is a flat bottom surface. The rear portion 12b of each undercover 12L, 12R is the part that is parallel to the road surface when the undercovers 12L, 12R are deployed. Therefore, when the vehicle 1 is driven with the left and right pair of undercovers 12L, 12R each in the deployed state, the pressure decreases as it goes towards the trailing edge 12d of the rear portion 12b. Thus, in vehicle 1 equipped with a pair of left and right undercovers 12L, 12R each having a rear portion 12b which is a flat bottom surface, when the vehicle is driven with the left and right pair of undercovers 12L, 12R each in the deployed state, air hits the left and right front wheels 11L, 11R in a straight line in the front-rear direction, making it possible to reduce the loss of kinetic energy. This will be described in detail with reference to Figures 13 and 14. Figure 13 shows the air pressure under the undercovers 12 (left undercover 12L, right undercover 12R) and the airflow at the front underside of the vehicle in vehicle 1 according to this embodiment. Figure 14 shows the air pressure under the undercovers 92 (left undercover 92L, right undercover 92R) and the airflow at the front underside of the vehicle in a comparative example vehicle.

[0081] As shown in Figure 14(a), the vehicle in the comparative example is equipped with undercovers 92 (left undercover 92L, right undercover 92R) at the front lower part of the vehicle, which are inclined such that the gap between the bottom surface of the rear 92b and the road surface narrows as you go from front to rear. As shown in Figure 14(b), the air pressure below each undercover 92 increases as you go from front to rear. Therefore, in the vehicle in the comparative example, as shown in Figure 14(c), the air introduced from the front is deflected outward in the vehicle width direction, and the air hitting the front wheels is directed diagonally outward. From this, it is thought that vortices are generated near the tire treads of the front wheels, resulting in a large loss of kinetic energy.

[0082] Furthermore, as explained using Figure 7, the under cover 92 of the comparative example vehicle has a sloping rear edge 92d (see Figure 7), so some of the air flowing from the front is deflected upward as it passes over the rear edge 92d of the under cover 92. This also causes the air to hit the front end of the front wheel at an oblique angle, which is thought to result in a large loss of kinetic energy.

[0083] In contrast, as shown in Figure 13(a), the vehicle 1 according to this embodiment is equipped with undercovers 12 (left undercover 12L, right undercover 12R) at the front lower part of the vehicle 1, which have a rear portion 12b that is parallel to the road surface when deployed. As shown in Figure 13(b), the air pressure below each undercover 12 decreases from front to rear. Therefore, in the vehicle 1 according to this embodiment, as shown in Figure 13(c), the air introduced from the front flows straight along the longitudinal direction and strikes each of the left and right front wheels 11 straight (in a direction substantially perpendicular to the tire tread). As a result, the generation of vortices near the front end 11a of the front wheel 11 (near the tire tread) is suppressed, and the loss of kinetic energy during driving can be kept to a minimum.

[0084] Furthermore, as explained with reference to Figure 6, the under cover 12 of the vehicle 1 according to this embodiment is configured such that its rear edge 12d has a straight shape that follows the vehicle width direction when viewed from below (see Figure 6, etc.). Therefore, even when air flowing from the front passes over the rear edge 12d of the under cover 12, it is not deflected upward. This also suppresses the generation of vortices near the front end (tire tread) 11a of the front wheel 11 in the vehicle 1 according to this embodiment, thereby reducing the loss of kinetic energy.

[0085] Vehicle 1 according to this embodiment does not have an under cover integrally formed in the vehicle width direction, but rather has a left under cover 12L and a right under cover 12R that are spaced apart from each other in the vehicle width direction. Therefore, compared to the case in which vehicle 1 has an under cover integrally formed in the vehicle width direction, the increase in vehicle weight and manufacturing cost is suppressed.

[0086] Furthermore, in the vehicle 1 according to this embodiment, a pair of left and right undercovers 12L and 12R are arranged in the range from the vicinity of the front end 13b of the front bumper 13 to the vicinity of the front end 11a of the front wheel 11 in the front-rear direction, and in the range between the left and right pair of front wheels 11 in the vehicle width direction. As described above, by arranging the pair of left and right undercovers 12 in the above range, the airflow that collides with the front end 11a of the front wheel 11 when the vehicle is running in the deployed state can be made straight in the front-rear direction. Therefore, in the vehicle 1 according to this embodiment, by arranging the pair of left and right undercovers 12L and 12R in the smallest possible range, the loss of kinetic energy during driving can be effectively reduced while suppressing an increase in vehicle weight and manufacturing cost.

[0087] Furthermore, the vehicle 1 according to this embodiment is equipped with a drive unit (actuator 17, link mechanism 16) that moves the left and right pair of undercovers 12L and 12R up and down. Therefore, when driving on a road surface with large irregularities, or when each undercover 12L, 12R and its surrounding parts are frozen in a low-temperature environment, it is possible to drive with the undercovers 12L and 12R raised (stored) without lowering them. Thus, the vehicle 1 can suppress interference with the road surface during driving and deformation and damage to each undercover 12L, 12R and its surrounding parts due to the up and down movement of the undercovers 12L and 12R.

[0088] The interpretation of "parallel" in the above context is the same as described above.

[0089] Furthermore, the vehicle 1 according to this embodiment is equipped with a PT cover 15 having a portion (proximity portion 15b) that is close to the rear edge portion 12d of each under cover 12L, 12R, and is positioned such that the height position of the proximity portion 15b on the bottom surface 15a of the PT cover is approximately the same as the height position of the rear edge portion 12d on the bottom surface 12c of each under cover 12L, 12R. Therefore, the air passing beneath each under cover 12L, 12R is smoothly (without stagnation) guided from the rear edge portion 12d of the under cover 12L, 12R to below the PT cover 15. Thus, the vehicle 1 is suitable for reducing the loss of kinetic energy when each under cover 12L, 12R is in an extended state.

[0090] Furthermore, in the vehicle 1 according to this embodiment, the bottom surface 15a of the PT cover 15 is flat in the portion 15c behind the aforementioned proximity point 15b. Therefore, in the vehicle 1, the air guided from the rear edge portions 12d of the left and right pair of undercovers 12L and 12R to the bottom of the PT cover 15 is smoothly (without stagnation) guided to the rear. Thus, the vehicle 1 is even more suitable for reducing the loss of kinetic energy when each undercover 12L and 12R is in the deployed state.

[0091] Furthermore, in this embodiment, the vehicle 1 is provided with the left under cover 12L and the right under cover 12R arranged and shaped symmetrically with respect to the vehicle's central axis Ax1. This allows the air flowing from the front to the underside of the vehicle 1 to flow symmetrically in the vehicle width direction. Therefore, the vehicle 1 is suitable for reducing kinetic energy loss while ensuring handling stability during driving.

[0092] Furthermore, in this embodiment, the vehicle 1 has a control unit 22 that acquires outside temperature information and vehicle speed information, and based on the acquired information (vehicle information), issues commands to raise / lower the left actuator 17L and the right actuator 17R. Therefore, when the outside temperature T is low and there is a concern that the road surface may freeze or that the undercovers 12L, 12R and the mechanisms of the surrounding parts may freeze, the left and right pair of undercovers 12L, 12R are not lowered (they are set to the retracted state), even when the vehicle speed V is high. Also, when the vehicle speed V is slow, it is presumed that the vehicle is driving in an urban area, so the undercovers 12L, 12R are not lowered (they are set to the retracted state). As a result, in the vehicle 1, when the outside temperature T is relatively low or the vehicle speed V is relatively slow, the undercovers 12L, 12R are raised to suppress deformation and damage to the undercovers 12L, 12R and the surrounding parts.

[0093] On the other hand, when the outside temperature T is relatively high and the vehicle speed V is judged to be relatively high, vehicle 1 lowers the pair of left and right undercovers 12L and 12R (to the deployed state) because freezing of the road surface, undercover 12 and its surrounding parts, and urban driving are not expected. This suppresses the generation of vortices near the front ends 11a of the left and right front wheels 11L and 11R, thereby reducing the loss of kinetic energy.

[0094] As described above, the vehicle 1 according to this embodiment can reduce kinetic energy loss by raising the undercovers 12L and 12R to suppress deformation and damage to the undercovers 12L and 12R and their surrounding parts during driving, and by lowering the undercovers 12L and 12R to suppress the occurrence of stagnation in airflow near the front ends 11a of the left and right front wheels 11L and 11R.

[0095] [Differentiation] In the above embodiment, the left under cover 12L and the right under cover 12R are arranged in a symmetrical relationship with respect to the vehicle's central axis Ax1 and have a symmetrical shape. However, in the present invention, they do not need to be symmetrical within the range of manufacturing tolerances.

[0096] Furthermore, although the above embodiment includes a PT cover 15 in addition to the under cover 12, the present invention does not necessarily require the inclusion of a PT cover 15.

[0097] Furthermore, in the above embodiment, the portion 15c of the PT cover 15 behind the adjacent portion 15b has a planar bottom surface 15a, but in the present invention, the bottom surface 15a of the above portion 15c may have a gently curved shape.

[0098] Furthermore, in the above embodiment, the control unit 22 acquires outside temperature information and vehicle speed information as vehicle information and decides whether to keep the under cover 12 in the retracted state or in the deployed state based on this information, but the present invention is not limited thereto. For example, navigation information may be acquired instead of vehicle speed information. This makes it possible to determine whether to raise or lower the under cover 12 by judging the road surface conditions that have been registered in advance as navigation information.

[0099] Furthermore, a system (for example, a laser measuring instrument) that monitors the road surface conditions in front of vehicle 1 can be used as a basis for judging the road surface conditions.

[0100] Furthermore, the vehicle according to the present invention does not necessarily have to be equipped with a control unit 22. Specifically, the driver operating the vehicle 1 may determine the environment of the road surface and driving route in which they intend to travel and issue a command to raise or lower the under cover 12.

[0101] Furthermore, although the above embodiment employs a structure in which the actuators 17L and 17R are fixed to the perimeter frame 18, the present invention also allows the actuators 17L and 17R to be fixed to other parts. For example, the actuators 17L and 17R can be fixed to the front side member or the front cross member.

[0102] Furthermore, in the above embodiment, a sealing member 19 is interposed between the under cover 12 and the front bumper 13, but in the present invention, it is not necessarily required to interpose a sealing member 19. [Explanation of Symbols]

[0103] 1 vehicle 11L left front wheel 11R Right front wheel 12 Undercover 12L Left Undercover 12R Right Undercover 15 Powertrain Undercover 17 Actuator (Drive Unit) 17L Left Actuator 17R Right Actuator 20. Outdoor temperature measurement unit 21 Vehicle speed measurement unit 22 Control Unit

Claims

1. At the front of the vehicle, a pair of front wheels are positioned at both ends in the width direction of the vehicle, A front bumper is provided positioned in front of the aforementioned pair of left and right front wheels and extending in the width direction at the front end of the vehicle, The portion of the vehicle in the longitudinal direction from near the front end of the front bumper to near the front ends of the pair of left and right front wheels, the left and right undercovers being positioned between the pair of left and right front wheels in the vehicle width direction, spaced apart from each other in the vehicle width direction, and each covering the bottom surface of the vehicle body, A drive unit that moves the pair of left and right undercovers up and down, Equipped with, Each of the pair of left and right undercovers, when lowered by the drive unit and in an extended state, has a flat bottom portion in the forward part from the rear edge, where the bottom surface is parallel to the road surface. vehicle.

2. The vehicle further comprises a powertrain under cover that is located close to the rear edges of the pair of left and right under covers in the longitudinal direction of the vehicle, and has a portion that extends rearward from the point of proximity, and covers the area below the vehicle's powertrain. The powertrain under cover is positioned such that, when the pair of left and right under covers are deployed, the bottom surface of the adjacent portion is at approximately the same height as the bottom surface of the rear edge of each under cover. The vehicle according to claim 1.

3. The powertrain under cover has a flat bottom surface in the portion of the area from the adjacent area to the rear. The vehicle according to claim 2.

4. The pair of left and right undercovers are provided with their respective rear edges having a straight shape along the width direction of the vehicle. The vehicle according to claim 1.

5. Assuming a vehicle center axis that passes through the center in the width direction and extends in the longitudinal direction of the vehicle, The pair of left and right undercovers are arranged symmetrically with respect to the vehicle's central axis and have shapes that are symmetrical to each other. A vehicle according to any one of claims 1 to 4.

6. An ambient temperature measuring unit that measures the ambient temperature, A vehicle speed measuring unit for measuring the vehicle's speed, A control unit that acquires ambient temperature information from the ambient temperature measurement unit and vehicle speed information from the vehicle speed measurement unit, and based on the acquired information, issues a command to the drive unit to raise or lower the pair of left and right undercovers, Furthermore, A vehicle according to any one of claims 1 to 4.

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