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, a pair of left and right undercovers 12, and a drive unit. The pair of left and right undercovers 12 are located from the area between the front wheels to the front, spaced apart from each other in the vehicle width direction between the front wheels, 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 deployed state, it has a rear portion (bottom flat portion) 12b in the front-rear direction, where the bottom surface is parallel to the road surface. The front edge portion 12f of the undercover 12 is inclined so that the inner portion forms an angle θ1 with respect to a virtual line L0 along the vehicle width direction, and the inward portion is positioned further forward in the vehicle width direction.

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 kinetic energy loss by suppressing eddy currents generated during traveling. When a vehicle is traveling, air flows from between the front bumper and the road surface to the lower side of the vehicle, and eddy currents may be generated below the vehicle to cause kinetic energy loss. Structures intended to suppress the generation of such eddy currents under 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 a front end of a front bumper to a vicinity of a 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 switchable in state between a stowed state in which a connecting portion between the front cover portion and the rear cover portion is lifted upward, and a deployed state in which the connecting 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 connecting portion, and the rear cover portion is provided to be inclined such that its height is displaced upward as it goes rearward from the connecting portion.

[0004] Patent Document 3 discloses a vehicle including flow regulating members (undercovers) respectively disposed on left and right sides in a 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 upper to lower as it goes from front to 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 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 pair of left and right undercovers are positioned in the front-rear direction of the vehicle, from the portion between the pair of left and right front wheels to the front, spaced apart from each other in the width direction between the pair of left and right front wheels, and each is provided to cover 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] Furthermore, when viewing each of the pair of left and right undercovers from below the vehicle, the portion of the front edge of the undercover that is on the inside in the vehicle width direction coincides with a virtual line along the vehicle width direction, or is inclined to be located further forward and inward relative to the virtual line in the vehicle width direction.

[0012] 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 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 straight in the front-rear direction, making it possible to reduce the loss of kinetic energy.

[0013] 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.

[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] Furthermore, in the above-described vehicle, when viewed from below, the inner portion of the leading edge of each undercover in the vehicle width direction (inner portion) coincides with the above-described line, or is inclined to be located further forward towards the inner side in the vehicle width direction. Therefore, when driving with the undercovers deployed, the air flowing from the front under the vehicle is deflected diagonally inward at the inner portion of the leading edge of each undercover. As a result, it is possible to suppress the diagonal air hitting the front wheels, which are positioned outward in the vehicle width direction behind each undercover, thereby reducing the loss of kinetic energy during driving.

[0016] 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.

[0017] In the vehicle according to the above embodiment, assuming a vehicle central axis passing through the center in the width direction and extending in the longitudinal direction of the vehicle, the pair of left and right undercovers may be arranged symmetrically with respect to the vehicle central axis and have shapes that are symmetrical with respect to each other.

[0018] In the above-described vehicle, the left and right undercovers are arranged and shaped symmetrically with respect to the vehicle's central axis, allowing air flowing from the front to the underside of the vehicle to flow symmetrically in the vehicle's width direction. Therefore, the above-described vehicle is suitable for reducing kinetic energy loss while ensuring handling stability during driving.

[0019] In the above embodiment of the vehicle, a powertrain under cover covering the lower part of the vehicle's driving powertrain may be further provided, extending from a position between the bottom flat portions of the left and right pair of under covers in the longitudinal direction of the vehicle to a position behind the left and right pair of under covers. In this case, the powertrain under cover may be positioned in close proximity to each of the bottom flat portions in the portion between the bottom flat portions of the left and right pair of under covers when they are in the deployed state.

[0020] The vehicle according to the above embodiment is equipped with a powertrain undercover positioned close to the flat bottom surface of each undercover, so that the air flowing rearward along the pair of left and right undercovers can be smoothly (without stagnation) guided to the area below the powertrain undercover.

[0021] In the vehicle according to the above embodiment, when the powertrain under cover is viewed from the side in the vehicle width direction, the powertrain under cover is arranged in an inclined position such that the bottom surface gradually slopes downward from top to bottom as it moves from front to rear, and the bottom surface may be made of a flat surface.

[0022] In the above-described vehicle, the bottom surface of the powertrain under cover is flat and is positioned in the above-described inclined manner, so that air flowing from the front can be smoothly (without stagnation) directed to the rear. For this reason, the above-described vehicle is even more suitable for reducing the loss of kinetic energy during driving.

[0023] 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 an instruction to the drive unit to raise or lower the pair of left and right undercovers based on the two acquired pieces of information.

[0024] In the vehicle according to the above aspect, the control unit acquires the outside air temperature information and the vehicle speed information, and issues a raise / lower instruction to the drive unit based on the acquired information (vehicle information). Therefore, when the outside air temperature is low and there is concern about freezing of the road surface or freezing of the mechanisms of each undercover and its peripheral portions, the pair of left and right undercovers are not lowered even when the vehicle speed is high. In addition, when the vehicle speed is low, it is estimated that the vehicle is traveling in an urban area or the like, so each undercover is not lowered. Thereby, 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 can be raised to suppress deformation and damage of each undercover and its peripheral portions.

[0025] 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 lowered since freezing or urban area traveling as described above is not assumed. Thereby, generation of eddy currents near the front ends of the front wheels can be suppressed, and loss of kinetic energy can be reduced. Effects of the Invention

[0026] 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 generation of stagnation of air flow near the front ends of the front wheels by lowering the undercover to reduce loss of kinetic energy. Brief Description of the Drawings

[0027] [Figure 1] This is a perspective view showing the front lower part of the vehicle according to the embodiment. [Figure 2] This is a bottom view showing the front lower part of the vehicle. [Figure 3] This is a schematic diagram showing the structure related to the movement of the underbody cover. [Figure 4] (a) is a side view showing the deployed state with the under cover lowered, and (b) is a side view showing the stowed state with the under cover 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 schematic diagram showing the configuration of the PT cover. [Figure 9] This is a schematic diagram showing the arrangement configuration of the PT cover in the comparative example. [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]

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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 12 (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.

[0032] 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. The left under cover 12L and the right under cover 12R are both located in the front-rear direction, from the area between the left front wheel 11L and the right front wheel 11R forward, and in the vehicle width direction, they are both located inward from the left front wheel 11L and the right front wheel 11R. The left under cover 12L and the right under cover 12R are spaced apart in the vehicle width direction, leaving a gap D between them.

[0033] 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).

[0034] 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. The pair of left and right deflectors 14 are each positioned directly in front of the front wheels 11. The left deflector 14L is positioned to the left (outside in the width direction) of the left under cover 12L, and the right deflector 14R is positioned to the right (outside in the width direction) of the right under cover 12R.

[0035] The PT cover 15 is positioned between the rear ends of the left under cover 12L and the right under cover 12R, extending behind the pair of under covers 12. Although not shown in the illustration, the PT cover 15 is positioned to cover the area below the powertrain (engine and drive motor) for driving the vehicle, which is mounted in the powertrain room at the front of the vehicle 1.

[0036] As shown in Figure 2, the left and right pair of undercovers 12 and PT cover 15 are positioned to avoid the wheel wells 1aL and 1aR.

[0037] 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.

[0038] 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.

[0039] 2. Up and down movement of undercover 12 Each of the left and right undercovers 12 is configured to be able to be raised and lowered 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 can 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.

[0040] 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).

[0041] 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.

[0042] 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, viewed from the side, 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.

[0043] As shown in Figure 5, the under cover 12 is provided such that the front portion 12a and the rear portion 12b are continuous in the front-rear direction. The rear portion 12b of the under cover 12 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 flat plane parallel to the road surface when deployed.

[0044] 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.

[0045] The front portion 12a of the under cover 12 is continuous with the rear portion 12b, and is composed of a smooth curved surface such that the bottom surface 12c gradually displaces upward as it moves from the point of continuity 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.

[0046] In its deployed state, the under cover 12 is positioned such that the front end of its front portion 12a is located a predetermined distance (for example, 70mm to 90mm) behind the front end of the front bumper 13.

[0047] As shown in Figure 6, when the under cover 12 is viewed from below, the under cover 12 has an outer edge portion 12h that defines the outside in the vehicle width direction and an inner edge portion 12g that defines the inside. The under cover 12 also has a front edge portion 12f that defines the front side of the front portion 12a, and a rear edge portion 12d and an inner rear edge portion 12e that define the rear side of the rear portion 12b.

[0048] The outer edge 12h and inner edge 12g 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 extends diagonally with respect to the vehicle width and is positioned to avoid the wheel well 1a. The inner rear edge 12e of the under cover 12 is positioned along the vehicle width.

[0049] Assuming a virtual line L0 along the vehicle width direction, the front edge portion 12f of the under cover 12 is inclined at an angle θ1 with respect to the virtual line L0, and has an inclined surface on the inside in the vehicle width direction that extends further forward towards the inner edge portion 12g. The effect of the under cover 12 having a front edge portion 12f formed in this shape will be explained by comparing it with the comparative example under cover 92 shown in Figure 7.

[0050] The comparative example undercover 92 shown in Figure 7 has an inclined surface on the inside in the vehicle width direction at the front edge portion 92f 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 92g. In an undercover 92 having a front edge portion 92f formed in this shape, the air FL9 that flows over the inclined surface of the front edge portion 92f and down to the undercover 92 flows diagonally outward, intersecting the inclined surface, and flows rearward along the bottom surface of the rear portion 92b.

[0051] In contrast, as shown in Figure 6, in the under cover 12 according to this embodiment, the air FL1 that flows over the inclined surface of the front edge 12f of the under cover 12 and flows downward towards the inner edge 12g in an oblique inward direction that intersects with the inclined surface. Then, the air FL1 that reaches the inner edge 12g changes its flow direction to follow the inner edge 12g and flows rearward along the vehicle's central axis Ax1 (see Figure 2).

[0052] Therefore, in the comparative example vehicle, the air FL9 that crosses the inclined surface of the leading edge 92f of the under cover 92 flows diagonally backward and reaches the front wheel. In contrast, in the vehicle 1 according to this embodiment, the air FL1 that crosses the inclined surface of the leading edge 12f of the under cover 12 changes its direction of flow along the inner edge 12g in the longitudinal direction, thereby preventing it from reaching the front end 11a of the front wheel 11 at an oblique angle.

[0053] In the vehicle 1 according to this embodiment, the inclination angle θ1 of the inclined surface of the leading edge portion 12f of the under cover 12 is 0deg to 10deg (for example, 5deg).

[0054] 4. Arrangement configuration of PT cover 15 The arrangement of the PT cover 15, which covers the lower part of the powertrain and extends from the position between the rear portions 12b of the under cover 12 to the position between the front wheels 11, will be explained with reference to Figures 8 and 9. Figure 8 is a side view of the PT cover 15 provided in the vehicle 1 according to this embodiment, and Figure 9 is a side view of the PT cover 95 provided in the vehicle according to a comparative example.

[0055] In the vehicle 1 according to this embodiment, the PT cover 15 is positioned between the rear portions 12b of the under cover 12 when it is deployed, close to each of the rear portions 12b, and arranged so as to minimize any vertical step difference. As shown in Figure 8, assuming a virtual plane L1 along the vehicle's horizontal axis, the PT cover 15 is positioned in an inclined posture such that its bottom surface is inclined at an angle θ2 with respect to the virtual plane L1, and its height gradually changes from top to bottom as it moves from front to bottom. In this embodiment, the bottom surface of the PT cover 15 is flat.

[0056] On the other hand, as shown in Figure 9, in the vehicle of the comparative example, the PT cover 95 has a front portion 95a which is composed of a curved surface such that its height is displaced from top to bottom as it goes from front to bottom. The portion of the PT cover 95 behind the front portion 95a is provided so as to be parallel to the road surface or displaced in height upward as it moves towards the rear.

[0057] In the comparative example shown in Figure 9, the air FL10 flowing from the front to the bottom of the vehicle collides with the front portion 95a of the PT cover 95, as indicated by arrow C. This can cause stagnation and blockage of airflow in that area. In contrast, in the vehicle 1 according to this embodiment shown in Figure 8, the PT cover 15 is positioned close to the under cover 12 in its deployed state, in an inclined position, and has a flat bottom surface. Therefore, stagnation of airflow caused by the PT cover 15 is suppressed.

[0058] 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.

[0059] As shown in Figure 10, the vehicle 1 further comprises an outside temperature measurement unit 19, a vehicle speed measurement unit 20, and a control unit 21. The outside temperature measurement unit 19 measures the outside temperature around the vehicle 1 and inputs the measured outside temperature information to the control unit 21.

[0060] The vehicle speed measurement unit 20 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 21.

[0061] The control unit 21 is configured with a microprocessor including an MPU / CPU, ASIC, ROM, RAM, etc., and memory. The control unit 21 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).

[0062] The control unit 21 includes a reference map storage unit 211, a cover state determination unit 212, and an actuator drive command unit 213. The reference map storage unit 211 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.

[0063] As shown in Figure 11, the reference map stored in the reference map storage unit 211 defines an ambient temperature threshold Ts, which is the ambient temperature threshold for raising or lowering the undercovers 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.

[0064] The cover state determination unit 212 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 211.

[0065] The actuator drive command unit 213 issues drive commands to the left actuator 17L and the right actuator 17R in a synchronous manner, based on the result determined by the cover state determination unit 212.

[0066] 6. Drive control of actuator 17 performed by control unit 21 The method for controlling the drive of the actuator 17, which is performed by the control unit 21, will be explained using Figure 12.

[0067] As shown in Figure 12, the control unit 21 determines whether the ambient temperature T obtained from the ambient temperature measurement unit 19 is lower than the ambient temperature threshold Ts defined in the reference map (see Figure 11) (step S1). If the control unit 21 determines that the ambient temperature T is lower than the ambient temperature threshold Ts (step S1: YES), the cover state determination unit 212 decides to put the left under cover 12L and the right under cover 12R into the retracted state, and the actuator drive command unit 213 issues an upward command to the left actuator 17L and the right actuator 17R (step S3).

[0068] On the other hand, if the control unit 21 determines that the outside temperature T is the same as or higher than the outside temperature threshold Ts (step S1: NO), it determines whether the vehicle speed V obtained from the vehicle speed measurement unit 20 is lower than the vehicle speed threshold Vs defined in the reference map (see Figure 11) (step S2). If the control unit 21 determines that the vehicle speed V is lower than the vehicle speed threshold Vs (step S2: YES), the cover state determination unit 212 decides to put the left under cover 12L and the right under cover 12R into the retracted state, and the actuator drive command unit 213 issues an upward command to the left actuator 17L and the right actuator 17R (step S3).

[0069] In response, if the control unit 21 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 212 determines that the left under cover 12L and the right under cover 12R should be deployed, and the actuator drive command unit 213 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 21 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.

[0070] The control unit 21 repeatedly executes steps S1 to S4 when the vehicle 1 is in the ignition state.

[0071] 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 deployed, the pressure decreases as it goes towards the rear edge 12d and inner rear edge 12e 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 deployed, air hits each of 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.

[0072] 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.

[0073] 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, each having 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 front-rear direction and strikes each of the left and right front wheels 11 straight. As a result, the generation of vortices near the front end 11a (near the tire tread) of the front wheels 11 is suppressed, and the loss of kinetic energy during driving can be kept to a minimum.

[0074] Furthermore, the 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. As a result, the increase in vehicle weight and manufacturing cost is suppressed compared to the case in which the vehicle 1 has an under cover integrally formed in the vehicle width direction.

[0075] Furthermore, the vehicle 1 according to this embodiment is equipped with drive units (actuators 17, link mechanism 16) that move 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 the undercovers 12L and 12R and their surrounding parts are frozen in a low-temperature environment, the vehicle can drive with the undercovers 12L and 12R raised (stored) without lowering them. Thus, the vehicle 1 can suppress deformation and damage to the undercovers 12L and 12R and their surrounding parts caused by driving and the up and down movement of the undercovers 12L and 12R.

[0076] Furthermore, in the vehicle 1 according to this embodiment, as seen in the bottom view in Figure 6, the inner portion of the front edge 12f of each under cover 12 (inner portion) is inclined at an angle θ1 such that it is located further forward in the vehicle width direction relative to the imaginary line L0. Therefore, when the vehicle is running with the under cover 12 deployed, the air FL1 flowing from the front below the vehicle 1 is deflected diagonally inward at the inner portion of the front edge 12f of each under cover 12. As a result, it is possible to reliably suppress the air from hitting the front wheels 11, which are positioned diagonally outward in the vehicle width direction behind each under cover 12. In this embodiment, the inner portion of the front edge 12f of the under cover 12 is inclined at an angle θ1 with respect to the imaginary line L0, but the inner portion of the front edge 12f may coincide with the imaginary line L0.

[0077] The interpretation of "parallel" in the above context is the same as described above.

[0078] 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 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.

[0079] Furthermore, since the vehicle 1 according to this embodiment is equipped with a PT cover 15 positioned close to the rear portions 12b of each under cover 12L, 12R, the air flowing rearward along the left and right pair of under covers 12L, 12R can be smoothly (without stagnation) guided to the area below the PT cover 15.

[0080] Furthermore, in this embodiment, the bottom surface of the PT cover 15 of the vehicle 1 is flat and is arranged in the inclined position shown in Figure 8, so that air flowing from the front can flow smoothly (without stagnation) to the rear. For this reason, the vehicle 1 is even more suitable for reducing the loss of kinetic energy during driving.

[0081] Furthermore, in this embodiment, the vehicle 1 has a control unit 21 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 12 and the mechanisms of their respective surrounding parts may freeze, the left and right pair of undercovers 12L and 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 and 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 and 12R are raised to suppress deformation and damage to the undercovers 12L and 12R and their respective surrounding parts.

[0082] 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 each of the left and right front wheels 11L and 11R, thereby reducing the loss of kinetic energy.

[0083] 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 each undercover 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.

[0084] [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.

[0085] 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.

[0086] Furthermore, in the above embodiment, the PT cover 15 has a flat bottom surface, but the present invention may also provide a PT cover with a gently curved bottom surface.

[0087] Furthermore, in the above embodiment of the vehicle 1, the control unit 21 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. However, the present invention is not limited to this. 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 based on the road surface conditions that have been registered in advance as navigation information.

[0088] 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.

[0089] Furthermore, the vehicle according to the present invention does not necessarily have to be equipped with a control unit 21. Specifically, the under cover 12 may be raised or lowered by the driver of the vehicle 1 in response to the environment of the road surface and the route on which the driver intends to travel.

[0090] Furthermore, while the vehicle 1 according to 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. [Explanation of symbols]

[0091] 1 vehicle 11L left front wheel 11R Right front wheel 12L Left Undercover 12R Right Undercover 12b Rear (bottom flat section) 12f leading edge 15 Powertrain Undercover 17L Left Actuator 17R Right Actuator 19. Outdoor temperature measurement unit 20. Vehicle speed measurement 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, The portion of the vehicle from the front to the front between the left and right front wheels in the longitudinal direction, comprising a pair of left and right undercovers positioned spaced apart from each other in the vehicle width direction between the left and right front wheels, 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. When viewing each of the pair of left and right undercovers from below the vehicle, the portion of the front edge of the undercover that is on the inner side in the vehicle width direction coincides with a virtual line along the vehicle width direction, or is inclined to be located further forward and inward relative to the virtual line in the vehicle width direction. vehicle.

2. 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. The vehicle according to claim 1.

3. The vehicle further comprises a powertrain under cover that covers the lower part of the vehicle's driving powertrain, extending from a position between the bottom flat portions of the left and right pair of under covers in the front-rear direction of the vehicle to a position behind the left and right pair of under covers. The powertrain under cover is positioned in the area between the bottom flat portions of the left and right under covers when they are in the deployed state, so as to be close to each of the bottom flat portions. The vehicle according to claim 1.

4. When the powertrain under cover is viewed from the side in the vehicle width direction, the powertrain under cover is arranged in an inclined position such that the bottom surface gradually slopes downward from top to bottom as it moves from front to rear, and the bottom surface is composed of a flat surface. The vehicle according to claim 3.

5. 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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