vehicle

Abstract

The present invention provides a vehicle that reduces the loss of kinetic energy by ensuring that air strikes the front wheels directly in the front-to-back direction while the vehicle is in motion. [Solution] The vehicle comprises a pair of left and right front wheels 11 and an under cover 12. The under cover 12 is positioned in front of the front wheels 11 in the longitudinal direction and between the front wheels 11 in the vehicle width direction, and is provided to cover the bottom surface of the vehicle body. The under cover 12 has a rear portion (bottom flat portion) 12b between the rear edge portion 12e and the front portion 12a, 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 travel to reduce kinetic energy loss. When a vehicle is traveling, air flows from the gap between the front bumper and the road surface to the lower side of the vehicle, and eddy currents may be generated under the vehicle, resulting in 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 position near 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 capable of state change between a stowed state where a connection portion between the front cover portion and the rear cover portion is raised 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 so as 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 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 left and right front wheels. When the flow regulating member is brought into a lowered state by the air actuator, the lower surface of the flow regulating member is provided with a curved surface whose height is displaced from top to bottom as it goes from the front to the lower side.

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 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 the structures disclosed in Patent Documents 1-3 are considered to be insufficient in suppressing the generation of vortices near the front end of the front wheel.

[0007] Specifically, in the structures disclosed in Patent Documents 1-3, the under cover is arranged such that, in the deployed state, the gap between the under cover and the road surface gradually narrows from the front of the vehicle towards the front end of the front wheel, resulting in high air pressure directly in front of the front wheel. Therefore, in the structures disclosed in Patent Documents 1-3, the air flowing between the under cover and the road surface does not hit the front end of the front wheel (tire tread) straight in the longitudinal direction, but rather hits it at an angle. As a result, in the structures disclosed in Patent Documents 1-3, vortices are generated near the front end of the front wheel during driving, and there is room for improvement in reducing the loss of kinetic energy.

[0008] The present invention aims to solve the above-mentioned problems and provides a vehicle that can reduce the loss of kinetic energy by having air strike the front wheels directly in the front-rear direction 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 and an under cover. 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 under cover is positioned in front of the pair of left and right front wheels in the longitudinal direction of the vehicle and between the pair of left and right front wheels in the width direction of the vehicle, and is provided to cover the bottom surface of the vehicle body.

[0010] In the vehicle according to this embodiment, the under cover has a flat bottom portion in the part forward 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 an under cover having a flat bottom portion. The flat bottom portion of the under cover is the part that is parallel to the road surface. Therefore, when the vehicle according to the above embodiment is in motion, the air pressure flowing backward between the bottom surface of the flat bottom portion of the under cover and the road surface decreases as it approaches the trailing edge of the flat bottom portion. Thus, in a vehicle equipped with an under cover having a flat bottom portion, when in motion, air hits the front wheels straight in the longitudinal direction, making it possible to reduce the loss of kinetic energy.

[0012] In the above, "parallel" includes not only cases where the bottom surface of the flat section of the underbody cover is perfectly parallel to the road surface, but also cases where it is slightly inclined to the road surface (for example, within 2 degrees). The same applies hereafter.

[0013] In the above embodiment of the vehicle, a front bumper may be further provided, which 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. In this case, the under cover may further have a front portion that is continuous with the front end of the bottom flat portion and extends to the vicinity of the front end of the front bumper. The front portion of the under cover may be composed of a smooth curved surface such that the bottom surface is gradually displaced upward from the point of continuity with the bottom flat portion towards the vicinity of the front end of the front bumper.

[0014] In the above-described vehicle, the front bottom surface of the underbody cover is composed of a smooth curved surface, so that the air introduced below the front bumper is guided along the front bottom surface to below the flat bottom section. For this reason, the above-described vehicle is suitable for reducing the loss of kinetic energy during driving compared to a vehicle in which there is a step or the like in front of the flat bottom section of the underbody cover.

[0015] Furthermore, in the vehicle according to the above embodiment, the front portion of the under cover may have arc-shaped front corners on both sides in the vehicle width direction.

[0016] In the above-described configuration, air flows smoothly from the front of the under cover along the arc-shaped front corners to both sides in the vehicle width direction during driving, making it suitable for reducing the loss of kinetic energy during driving.

[0017] In the above-described embodiment, it is preferable that at least the bottom flat portion of the under cover is configured to be movable in the vertical direction.

[0018] In this configuration, at least the bottom flat portion of the underbody cover moves up and down. Therefore, even when the underbody cover may interfere with the road surface, such as when the vehicle is driving on a road with significant undulations, the movement of at least the bottom flat portion of the underbody cover upwards can suppress deformation and damage to the underbody cover.

[0019] In the vehicle according to the above embodiment, the under cover may be further provided with a drive unit for moving the under cover up and down, and the bottom flat portion may be such that when it is in an extended state lowered by the drive unit, the bottom surface is parallel to the road surface.

[0020] In the vehicle according to the above aspect, the bottom flat portion of the undercover is parallel to the road surface when in the deployed state. For this reason, when the vehicle according to the above aspect travels, the pressure of the air flowing rearward between the bottom surface of the bottom flat portion of the undercover and the road surface decreases as it travels toward the rear edge of the bottom flat portion. Therefore, in a vehicle provided with an undercover having a bottom flat portion, when traveling with the undercover in the deployed state, air strikes the front wheels straight in the front-rear direction, making it possible to reduce the loss of kinetic energy.

[0021] Further, since the vehicle according to the above aspect includes the drive unit that moves the undercover up and down, when traveling on a road surface with large unevenness, or when the undercover and its surrounding parts are frozen in a low-temperature environment, it is possible to travel with the undercover raised without being lowered. Therefore, the vehicle according to the above aspect can suppress deformation and damage of the undercover and its surrounding parts accompanying traveling and the vertical movement of the undercover.

[0022] In the vehicle according to the above aspect, the vehicle may further include a control unit. The control unit acquires vehicle information of the vehicle, and issues a command to the drive unit to raise or lower the undercover based on the acquired vehicle information.

[0023] Since the vehicle according to the above aspect includes the control unit that issues a raise / lower command to the drive unit based on the acquired vehicle information, it is possible to lower the undercover under feasible conditions to reduce kinetic energy loss, and when the conditions are not met, raise the undercover to suppress deformation and damage of the undercover and its surrounding parts. Therefore, the vehicle according to the above aspect is suitable for reliably reducing kinetic energy loss and suppressing deformation and damage of the undercover and its surrounding parts, compared with the case where the driver issues a raise / lower command to the drive unit.

[0024] In the vehicle according to the above aspect, the undercover may further include a fixed frame fixed to the bottom surface of the vehicle body, and a deformable deformable member connecting at least the front end portion of the bottom surface flat portion and the fixed frame. The deformable member is made of a softer material than the bottom surface flat portion, and is configured to deform when the bottom surface flat portion interferes with a road surface, thereby enabling upward movement of the bottom surface flat portion.

[0025] In the vehicle according to the above aspect, when the bottom surface flat portion interferes with a road surface, the deformable member connecting the front end portion of the undercover and the fixed frame deforms, thereby enabling upward movement of the bottom surface flat portion. As a result, deformation and damage to the undercover and its peripheral portions can be suppressed. [Advantageous Effects of Invention]

[0026] The vehicle according to each of the above aspects can suppress the generation of vortices near the front end of the front wheels and reduce the loss of kinetic energy by allowing air to strike the front wheels straight in the front-rear direction during traveling. [Brief Description of Drawings]

[0027] [Figure 1] It is a perspective view showing a front lower portion of the vehicle according to the embodiment of the present invention. [Figure 2] It is a bottom view showing a front lower portion of a vehicle. [Figure 3] It is a schematic diagram showing a structure related to the movability of the undercover. [Figure 4] (a) is a side view showing a deployed state where the undercover is lowered, and (b) is a side view showing a stored state where the undercover is raised. [Figure 5] It is a side view for explaining the arrangement position and shape of the undercover. [Figure 6] It is a bottom view for explaining the shape of the undercover. [Figure 7]This is a cross-sectional view illustrating the positional relationship between the undercover and the PT cover in their deployed state. [Figure 8] (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 9] (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. [Figure 10] This is a perspective view of the under cover and its surrounding area, showing the main parts of a vehicle according to another embodiment of the present invention, viewed from a diagonal lower left front. [Figure 11] Figure 10 shows an enlarged perspective view of the underbody, seen from the lower right front. [Figure 12] Figure 1 is a bottom view of the left portion of the underbody cover. [Figure 13] Figure 1 is a side view of the front portion of the left side of the under cover. [Figure 14] A perspective view showing the front lower part of a vehicle according to yet another embodiment of the present invention. [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 left and right front wheels 11 (left front wheel 11L, right front wheel 11R), an under cover 12, a front bumper 13, and a pair of left and right deflectors 14 at the front lower part of the vehicle. The pair of left and right front wheels 11 are positioned at both ends in the width direction of the vehicle at the front of the vehicle 1.

[0032] The front bumper 13 is positioned in front of the pair of left and right front wheels 11 and extends in the width direction at the front end of the vehicle 1. The under cover 12 is positioned in front of the pair of left and right front wheels 11 in the front-rear direction and in the area between the left front wheel 11L and the right front wheel 11R in the width direction. The under cover 12 is provided to cover the bottom surface of the vehicle body in the said area. In this embodiment, the under cover 12 is formed using a resin material (for example, PP: polypropylene).

[0033] The left and right pair of deflectors 14 are each positioned directly in front of the front wheels 11. Furthermore, as shown in Figure 2, the deflectors 14 are positioned on both outer sides in the vehicle width direction relative to the under cover 12. In this embodiment, the deflectors 14 are formed using elastomer as an example.

[0034] As shown in Figure 2, the vehicle 1 further includes a powertrain under cover (PT cover) 15 located behind the under cover 12, in the area between the left front wheel 11L and the right front wheel 11R. The PT cover 15 is provided to cover the underside of the powertrain (e.g., engine and traction motor) mounted in the powertrain room.

[0035] Vehicle 1 of this embodiment has the following configuration, which allows the under cover 12 to move vertically. Note that Vehicle 1 only needs to have a configuration in which at least the bottom flat portion (rear portion 12b) can move vertically.

[0036] Specifically, as shown in Figure 3, the vehicle 1 includes an actuator 17 and a link mechanism 16 that connects the actuator 17 and the under cover 12. 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.

[0037] The under cover 12 is configured to move up and down as indicated by arrow A by the drive of the actuator 17. The configuration related to the drive control of the actuator 17 will be described later.

[0038] 2. Up and down movement of undercover 12 As described above, the under cover 12 is configured to be able to be raised and lowered by a drive unit including an actuator 17. In the vehicle 1 according to this embodiment, the under cover 12 can change between a deployed state, where it is lowered, and a retracted state, where it is raised. The deployed state and the retracted state of the under cover 12 will be explained with reference to Figure 4.

[0039] As indicated by arrow B1 in Figure 4(a), the under cover 12 can assume a position where it protrudes below the lower edge 13a of the front bumper 13 (deployed state).

[0040] On the other hand, as shown by arrow B2 in Figure 4(b), the under cover 12 can be positioned in a way that at least a portion of it is stored inside the front bumper 13 (stored state). In this embodiment, one example of the stored state is that a portion of the under cover 12 protrudes below the lower edge 13a of the front bumper 13, but a configuration in which the entire under cover 12 rises above the lower edge 13a of the front bumper 13 may also be adopted.

[0041] 3. Detailed structure of Undercover 12 The detailed structure of the under cover 12 will be explained using Figures 5 and 6. Figure 5 is a side view of the under cover 12 in its deployed state, and Figure 6 is a bottom view of a part of the under cover 12, viewed from below.

[0042] 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 extends forward from the trailing edge portion 12e, which is located in front of the front end (front end of the tire tread) 11a of the front wheel 11, when deployed, and has a flat bottom surface 12c. The rear portion 12b of the under cover 12 is provided such that the bottom surface 12c is parallel to the road surface when deployed. In other words, the rear portion 12b of the under cover 12 is a flat bottom portion.

[0043] Furthermore, the rear edge portion 12e of the under cover 12 may be positioned rearward in the longitudinal direction to the position of the rotation center of the front wheels 11, within the range between the left and right front wheels 11 in the vehicle width direction. In that case, the flat bottom surface 12c can be extended rearward to the position of the rotation center of the front wheels 11 within the range between the left and right front wheels 11. As a result, the maximum longitudinal length of the under cover 12 becomes the length from the front end of the front bumper 13 to the position of the rotation center of the front wheels 11 (approximately 770 mm). This makes it possible to sufficiently reduce the air pressure while directing the air straight backward over a long distance within the range between the left and right front wheels 11.

[0044] In the above, "parallel" includes not only cases where the bottom surface of the flat section of the underbody cover is perfectly parallel to the road surface, but also cases where it is slightly inclined to the road surface (for example, within 2 degrees). 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 (preferably about 40 mm).

[0046] 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.

[0047] As shown in Figure 6, when the under cover 12 is viewed from below, the rear portion 12b is provided such that its outer edge in the vehicle width direction is aligned with the longitudinal direction of the vehicle 1. The under cover 12 is provided with a rear edge portion 12e that is straight and aligned with the vehicle width direction. That is, the rear edge portion 12e of the under cover 12 is formed to be straight and not inclined with respect to the vehicle width direction, nor does a part of it protrude toward the rear.

[0048] The front portion 12a has a front corner portion 12d that has an arc shape with a radius of curvature R2. In this embodiment, the radius of curvature R2 is, for example, 20 mm to 200 mm (preferably about 30 mm).

[0049] Here, when the undercover 12 is in the deployed state, if the length of the front part 12a in the front-rear direction is L12a and the length of the rear part 12b in the front-rear direction is L12b, then L12a and L12b are provided to satisfy the following relationship.

[0050] 300≦(L12a+L12b)≦500··(1)

[0051] 4. Height position of the undercover 12 in the deployed state The height position of the under cover 12 in the deployed state will be explained using Figure 7. Figure 7 is a schematic cross-sectional view showing the under cover 12 in the deployed state and the PT cover 15 positioned behind the under cover 12.

[0052] As shown in Figure 7, in the unfolded state, the under cover 12 is positioned such that its bottom surface 12c is at approximately the same height as the bottom surface 15a of the PT cover 15 at its rear edge 12e. However, there may be a slight difference in height between the bottom surface 12c of the under cover 12 and the bottom surface 15a of the PT cover 15. For example, there may be a difference in height equal to the thickness of the under cover 12.

[0053] 5. Control configuration for the movement of the under cover 12 Vehicle 1 includes a control unit 19 that performs drive control of the actuator 17, as shown in Figure 3, in order to control the movement (up and down movement) of the under cover 12. An example of the configuration will be briefly explained.

[0054] The control unit 19 is configured with a microprocessor including an MPU / CPU, ASIC, ROM, RAM, etc., and memory. The control unit 19 executes firmware etc. pre-stored in memory to acquire vehicle information such as outside temperature information and vehicle speed information obtained from measurement means mounted on the vehicle (such as an outside temperature sensor and a vehicle speedometer), and performs drive control of the actuator 17.

[0055] In other words, the control unit 19 first determines whether the under cover 12 should be in an deployed state (lowered state) or a retracted state (upper state) based on the acquired vehicle information. For example, the control unit 19 decides to deploy the under cover 12 when the outside temperature is above a predetermined temperature and the vehicle speed is above a predetermined speed, and decides to retract it in other cases (i.e., when there is a risk of the under cover 12 interfering with the road surface due to snow or ice accumulation on the road surface, or when driving on a road surface with large undulations). Then, the control unit 19 executes drive control of the actuator 17 (i.e., the operation of lowering or raising the under cover 12) based on the determined deployed or retracted state.

[0056] 6. Effects The vehicle 1 according to this embodiment is equipped with an under cover 12 having a rear portion 12b which is a flat bottom portion. The rear portion 12b of the under cover 12 is the part that is parallel to the road surface, and in the above embodiment, it is the part that is parallel to the road surface when the under cover 12 is in the deployed state. Therefore, when the vehicle 1 is driving with the under cover 12 in the deployed state, the pressure of the air flowing backward between the bottom surface 12c of the rear portion 12b of the under cover 12 and the road surface decreases as it approaches the rear edge portion 12e of the under cover 12.

[0057] Therefore, in a vehicle 1 equipped with an under cover 12 having a rear portion 12b which is a flat bottom portion, when the vehicle is driven with the under cover 12 deployed, air hits the front wheels 11 in a straight line along the longitudinal direction, making it possible to reduce the loss of kinetic energy. This will be explained in detail with reference to Figures 8 and 9. Figure 8 shows the air pressure under the under cover 12 and the airflow at the front bottom of the vehicle in vehicle 1 according to this embodiment. Figure 9 shows the air pressure under the under cover 92 and the airflow at the front bottom of the vehicle in a comparative example vehicle.

[0058] As shown in Figure 9(a), the vehicle in the comparative example is equipped with an under cover 92 at the front lower part of the vehicle, which is inclined such that the gap between the bottom surface of the rear 92b and the road surface narrows as it moves from front to rear. As shown in Figure 9(b), the air pressure below the under cover 92 increases as it moves from front to rear. Therefore, in the vehicle in the comparative example, as shown in Figure 9(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.

[0059] In contrast, as shown in Figure 8(a), the vehicle 1 according to this embodiment is equipped with an under cover 12 at the front lower part of the vehicle 1, which has a rear portion 12b that is parallel to the road surface when deployed. As shown in Figure 8(b), the air pressure below the under cover 12 decreases as it moves from the front to the rear. Therefore, in the vehicle 1 according to this embodiment, as shown in Figure 8(c), the air introduced from the front flows straight along the longitudinal direction and hits the front wheel 11 straight. As a result, the generation of vortices near the front end 11a (near the tire tread) of the front wheel 11 is suppressed, and the loss of kinetic energy during driving can be kept to a minimum.

[0060] Furthermore, since the vehicle 1 according to this embodiment is equipped with a drive unit (actuator 17, link mechanism 16) for moving the under cover 12 up and down, it is possible to drive with the under cover 12 raised without lowering it when driving on a road surface with large irregularities or when the under cover 12 and its surrounding parts are frozen at low temperatures. Thus, the vehicle 1 can suppress deformation and damage to the under cover 12 and its surrounding parts caused by driving and the up and down movement of the under cover 12.

[0061] The interpretation of "parallel" in the above context is the same as described above.

[0062] Furthermore, in this embodiment, since the bottom surface 12c of the front portion 12a of the under cover 12 of the vehicle 1 is composed of a smooth curved surface, the air introduced below the front bumper 13 flows along the bottom surface 12c of the front portion 12a and is guided downward to the rear portion (bottom flat portion) 12b without separation. For this reason, the vehicle 1 is suitable for reducing the loss of kinetic energy during driving compared to cases in which there is a step or the like in front of the bottom flat portion of the under cover.

[0063] Furthermore, the vehicle 1 according to this embodiment includes a control unit 19 that issues commands to the actuator 17 to raise / lower based on acquired vehicle information. This allows the under cover 12 to be lowered under all possible conditions to reduce kinetic energy loss, while raising the under cover 12 when the conditions are not met to suppress deformation and damage to the under cover 12 and its surrounding parts. Therefore, the vehicle 1 is more suitable for reliably reducing kinetic energy loss and suppressing deformation and damage to the under cover 12 and its surrounding parts compared to when the driver commands the actuator 17 to raise / lower.

[0064] Furthermore, in this embodiment, the vehicle 1 has a control unit 19 that acquires outside temperature information and vehicle speed information as vehicle information, and based on the acquired information, issues an upward / downward command to the actuator 17. Therefore, if the outside temperature is lower than the outside temperature threshold and there is a concern about the road surface freezing or freezing of the under cover or drive unit, the under cover 12 will not be lowered (it will remain in the retracted state) even if the vehicle speed is above the vehicle speed threshold. Also, if the vehicle speed is slower than the vehicle speed threshold, it is estimated that the vehicle is driving in an urban area, so the under cover 12 will not be lowered (it will remain in the retracted state). As a result, in the vehicle 1, when the outside temperature is lower than the outside temperature threshold or when the vehicle speed is lower than the vehicle speed threshold, the under cover 12 will remain in the retracted state, thereby suppressing deformation and damage to the under cover 12 and its surrounding parts.

[0065] On the other hand, if vehicle 1 is determined to have an outside temperature above the outside temperature threshold and a vehicle speed above the vehicle speed threshold, then the under cover 12 is deployed because conditions such as freezing or driving in urban areas are not expected. This reduces the loss of kinetic energy.

[0066] Furthermore, in the vehicle 1 according to this embodiment, a reference map in which an outside temperature threshold and a vehicle speed threshold are defined may be pre-stored in the reference map storage unit of the control unit. The control unit 19 can acquire outside temperature information and vehicle speed information and determine whether the under cover 12 is rising or falling based on this information and the reference map.

[0067] Furthermore, since the vehicle 1 according to this embodiment is equipped with a drive unit having an actuator 17 and a link mechanism 16, it is possible to reduce manufacturing costs without employing a special structure for raising / lowering the under cover 12.

[0068] Furthermore, in vehicle 1, since the actuator 17 is fixed to the perimeter frame 18, the height positions of the under cover 12 when raised and lowered relative to the underside of vehicle 1 can be reliably defined. That is, since the perimeter frame 18 does not move up and down relative to the structural members of the vehicle body, fixing the actuator 17 to the perimeter frame 18 is suitable for defining the reference position of the under cover 12 when vibrations are added during driving.

[0069] Furthermore, since the perimeter frame 18 is located at the front of the vehicle 1 and close to the area where the under cover 12 is to be installed, there is no need to interpose a long bracket or the like to fix the actuator 17. Therefore, the actuator 17 can be securely fixed to the vehicle body.

[0070] As described above, the vehicle 1 according to this embodiment can reduce the loss of kinetic energy during driving by suppressing deformation or damage to the under cover 12 and its surrounding parts during driving by raising the under cover 12, and by suppressing the generation of vortices near the front end 11a of the front wheel 11 by lowering the under cover 12 under possible conditions.

[0071] [Differentiation] In the vehicle 1 according to the above embodiment, the rear edge 12e of the under cover 12 is positioned in front of the front wheel 11, but the present invention is not limited thereto. For example, the under cover 12 may be positioned such that the rear edge 12e is located around the axle of the front wheel 11 in the longitudinal direction.

[0072] Furthermore, although the vehicle 1 according to the above embodiment has a front portion 12a of the under cover 12 that is formed of a curved surface, the present invention is not limited thereto. The under cover 12 may have a front portion formed of a flat slope leading to a bottom surface, as long as the air flowing under the front of the vehicle 1 is guided to the rear portion 12b of the under cover 12 without separation. Also, the under cover 12 does not necessarily have to have a front portion 12a.

[0073] Furthermore, in the above embodiment of the vehicle 1, the control unit 19 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.

[0074] 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.

[0075] Furthermore, the vehicle according to the present invention does not necessarily have to include a control unit 19. Specifically, the driver operating the vehicle 1 may determine the environment of the road surface and driving route to be traveled and raise / lower the under cover 12 accordingly.

[0076] Furthermore, while the vehicle 1 according to the above embodiment employs a structure in which the actuator 17 is fixed to the perimeter frame 18, the present invention also allows the actuator 17 to be fixed to other parts. For example, the actuator 17 can be fixed to the front side member or the front cross member.

[0077] [Other embodiments] In the above embodiment, the under cover 12 is shown to be positioned in an upper retracted state or a lower extended state depending on conditions such as ambient temperature and vehicle speed by moving up and down by an actuator 17. However, the present invention is not limited to this, and the under cover 12 may be fixed in the lower extended state. In that case as well, the loss of kinetic energy can be reduced because the air hits the front wheels straight in the front-rear direction while driving.

[0078] However, if the under cover 12 is fixed in its lower, unfolded position and the vehicle 1 drives over a road surface with significant undulations, a new problem arises: the under cover 12 may interfere with the road surface.

[0079] Therefore, the under cover 12 should be designed so that at least the bottom flat portion moves up and down. This allows deformation and damage to the under cover 12 to be suppressed, even if there is a risk of the under cover 12 interfering with the road surface, by moving at least the bottom flat portion of the under cover 12 upward.

[0080] The configuration in which at least the bottom flat portion of the under cover 12 moves up and down is not limited to the configuration in which the entire under cover 12 is moved up and down by the actuator 17 as in the above embodiment, but may also be configured such that only the bottom flat portion 21 can be partially moved upward when it comes into contact with the road surface, as shown in Figures 10 to 14 below.

[0081] In other words, as shown in Figures 10 to 14, the under cover 20 according to another embodiment of the present invention further includes, in addition to a bottom flat portion 21 consisting of a plane that can move up and down, a fixed frame 22 fixed to the bottom surface of the front bumper 13 as the bottom surface of the vehicle body, and a deformable deformable member 23 connecting at least the front end of the bottom flat portion 21 to the fixed frame 22.

[0082] The bottom flat section 21 has a flat bottom surface that extends substantially parallel to the road surface GR. In Figure 13, the lowest end 21c of the bottom flat section 21 is shown protruding at a corner to emphasize its position. The height H of the lowest end 21c of the bottom flat section 21 from the road surface GR is set such that the bottom flat section 21 does not interfere with the road surface when driving on a flat road surface, but interferes with the road surface when there are obstacles or steps of a certain height or higher.

[0083] The deformable member 23 is a film-like body made of a material softer than the bottom flat portion 21, and is configured to deform when the bottom flat portion 21 comes into contact with the road surface, thereby enabling upward movement of the bottom flat portion 21. Specifically, it is configured as follows.

[0084] First, the front end 21a and the side ends 21b on both sides in the vehicle width direction, excluding the rear end 21c, are spaced apart from the fixed frame 22. On the other hand, the rear end 21c of the bottom flat portion 21 is fixed to the fixed frame 22 (specifically, the rear fixing portion 22a fixed to the vehicle body's cross member, etc.). Therefore, the bottom flat portion 21 is partially supported by the fixed frame 22 at the aforementioned rear end 21c in a cantilevered state.

[0085] As described above, with the bottom flat portion 21 supported in a cantilevered state, the deformation member 23 connects the area between the fixed frame 22 and the area between the front end 21a and the rear end 21c of both side ends 21b, as at least the front end of the bottom flat portion 21. As a result, as shown in Figure 13, the deformation member 23 deforms in a direction that is compressed vertically as the bottom flat portion 21 moves upward when it comes into contact with the road surface, thereby enabling the bottom flat portion 21 to move upward.

[0086] In the vehicle according to the above embodiment, when the bottom flat portion 21 of the under cover 20 comes into contact with the road surface, a deformation member connecting the front end of the under cover and the fixing frame deforms, allowing the bottom flat portion 21 to move upward. This suppresses deformation and damage to the under cover 20 and its surrounding parts.

[0087] [Further embodiments] In the vehicle 1 of the above embodiment, as shown in Figure 1, each of the left and right pairs of deflectors 14 is positioned directly in front of each of the pair of front wheels 11, but the present invention is not limited thereto. In yet another embodiment of the present invention, as shown in Figure 14, the deflectors 14 may be omitted and the left and right ends of the under cover 12 may be extended in the vehicle width direction to cover the front of the front wheels 11. In this configuration, even if the deflectors 14 are omitted, the wider under cover 12 reduces the wind hitting the front wheels 11 while driving, and the air hits the front wheels 11 directly in the front-rear direction, thereby reducing the loss of kinetic energy. [Explanation of Symbols]

[0088] 1 vehicle 11 Front Wheel 11a Front end 12 Undercover 12b Rear (bottom flat section) 13 Front Bumper 17 Actuators 18 Perimeter Frame 19 Control Unit 20 Undercover 21 Flat bottom section 22 Fixed Frame 23 Deformed member

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, An under cover is provided in front of the pair of left and right front wheels in the longitudinal direction of the vehicle, and between the pair of left and right front wheels in the width direction of the vehicle, and covers the bottom surface of the vehicle body. Equipped with, The under cover has a flat bottom portion in the part forward from the rear edge, where the bottom surface is parallel to the road surface. vehicle.

2. The vehicle further comprises a front bumper 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 under cover further has a front portion that is continuous with the front end of the bottom flat portion and extends to the vicinity of the front end of the front bumper, The front portion of the under cover is composed of a smooth curved surface such that the bottom surface gradually displaces upward from the point of continuity with the bottom flat portion towards the vicinity of the front end of the front bumper. The vehicle according to claim 1.

3. The front portion of the under cover has front corners that are arc-shaped on both sides in the vehicle width direction. The vehicle according to claim 1 or claim 2.

4. The under cover has a configuration in which at least the bottom flat portion is movable in the vertical direction. The vehicle according to claim 1 or claim 2.

5. The under cover is further provided with a drive unit that moves it up and down. When the bottom flat portion is in the deployed state lowered by the drive unit, the bottom surface becomes parallel to the road surface. The vehicle according to claim 4.

6. The system further includes a control unit that acquires vehicle information of the vehicle and issues a command to the drive unit to raise or lower the under cover based on the acquired vehicle information. The vehicle according to claim 5.

7. The under cover further comprises a fixed frame fixed to the bottom surface of the vehicle body, and a deformable deformable member connecting at least the front end of the bottom flat portion to the fixed frame. The deformable member is made of a material softer than the bottom flat portion and is configured to deform when the bottom flat portion comes into contact with the road surface, thereby enabling upward movement of the bottom flat portion. The vehicle according to claim 4.

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