Vehicle understructure

Abstract

To inhibit snow from entering through a connection part of two covers existing on the bottom of a vehicle.SOLUTION: A vehicle understructure 12 is adapted to a vehicle 10 having a battery 20 installed under the floor. The vehicle understructure 12 includes an undercover 30 that is disposed below the battery 20 and forms at least part of the vehicle bottom. The undercover 30 includes a front cover 32 and a rear cover 34 located behind the front cover 32 in the vehicle. By superposing a rear end 32b of the front cover 32 on a front end 34f of the rear cover 34, a connection part 38 of the covers 32 and 34 is formed. One of the front cover 32 and the rear cover 34 that is located above at the connection part 38 has a projection 36, which projects downward in the vehicle, at a position adjoining the connection part 38.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle underbody structure, and more particularly to a vehicle underbody structure applicable to a vehicle having a battery mounted under the floor.

Background Art

[0002] Conventionally, electric vehicles such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs) have been known. An electric vehicle is equipped with a battery that supplies electric power to a drive motor. Some electric vehicles have a battery arranged under the floor. An under cover that forms at least a part of the vehicle bottom surface is provided below this battery.

[0003] Patent Document 1 discloses an underfloor structure of an electric vehicle in which a battery unit mounted under the floor of the vehicle is covered with a battery under cover.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The under cover may be composed of a plurality of covers. This under cover includes a front cover and a rear cover arranged behind the front cover of the vehicle. By overlapping the rear end of the front cover and the front end of the rear cover, a connection portion of these covers is formed.

[0006] In a vehicle equipped with such an under cover, when the vehicle travels on a snow-covered road, there is a risk that snow may enter the vehicle interior from the overlapping portion (connection portion) of the front cover and the rear cover. Therefore, a structure that can suppress the intrusion of snow from the overlapping portion (connection portion) of the two covers is desired.

[0007] An object of the present invention is to provide a vehicle underbody structure capable of suppressing snow from entering from a connection portion between two covers at the bottom of a vehicle.

Means for Solving the Problems

[0008] The vehicle underbody structure according to the present invention is a vehicle underbody structure applied to a vehicle in which a battery is mounted under the floor, and includes an under cover disposed below the battery and forming at least a part of the vehicle bottom surface. The under cover includes a front cover and a rear cover disposed behind the front cover of the vehicle. A connection portion of these covers is formed by overlapping the rear end of the front cover and the front end of the rear cover. The cover located above at the connection portion of the front cover and the rear cover has a protruding portion protruding downward from the vehicle at a position adjacent to the connection portion.

[0009] Further, in the vehicle underbody structure according to the present invention, at the connection portion, the front end of the rear cover may be located above the rear end of the front cover, and the rear cover may have the protruding portion behind the connection portion of the vehicle.

[0010] Further, in the vehicle underbody structure according to the present invention, at the connection portion, the vertical distance in the vehicle up and down direction from the lower surface of the front end of the rear cover to the upper and lower surfaces of the top of the protruding portion of the rear cover is defined as the height of the protruding portion, and the vehicle front and rear direction from the top of the protruding portion of the rear cover to the position where the lower surface height of the rear cover does not change from there toward the rear of the vehicle The distance is defined as the return distance of the protruding portion, and the return distance of the protruding portion may be twice as long as the height of the protruding portion.

[0011] Further, in the vehicle underbody structure according to the present invention, at the connection portion, the rear end of the front cover may be located above the front end of the rear cover, and the front cover may have the protruding portion in front of the connection portion of the vehicle.

Effects of the Invention

[0012] According to the present invention, when the vehicle is running and snow drifts from the cover located above at the connection part between the front cover and the rear cover toward the cover located below, the protruding part can push the snow downward to prevent the snow from advancing to the end face of the lower cover that appears on the bottom surface of the vehicle. Therefore, it is possible to suppress the intrusion of snow into the vehicle interior from the overlapping part (connection part) of the two covers.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described herein. The same elements are denoted by the same reference numerals in all the drawings, and redundant explanations are omitted. In the following description, unless otherwise specified, the terms indicating directions and orientations such as front, rear, left, right, up, and down represent the directions and orientations related to the vehicle. In each figure, the direction of arrow FR represents the front, the direction of arrow UP represents the upper, and the direction of arrow RH represents the right.

[0015] FIG. 1 is a cross-sectional view schematically showing the vehicle lower structure 12, and schematically shows the whole vehicle 10 on the upper side. On the upper side of the figure, the cross-section of the part of the vehicle 10 surrounded by the broken line (the vehicle lower part between the front wheel 14 and the rear wheel 16) is enlarged, which is the vehicle lower structure 12 on the lower side of the figure. FIG. 1 also shows the ground 200 and the accumulated snow 202.

[0016] The vehicle 10 is a plug-in hybrid vehicle (PHEV) and is an automobile. Note that the vehicle 10 may be other electric vehicles such as a battery electric vehicle (BEV) or a hybrid electric vehicle (HEV). A battery 20 is mounted under the floor of the vehicle 10. That is, the battery 20 is disposed under the floor panel 18 of the vehicle. The upper side of the floor panel 18 is the passenger compartment.

[0017] The battery 20 includes a battery body 22, an upper case 24, and a lower case 26. The battery body 22 is configured to include a plurality of battery cells. The battery body 22 supplies electric power to a drive motor (not shown) for driving the vehicle 10, an air conditioner, and the like. Further, the battery body 22 is charged by external electric power or regenerative electric power during deceleration of the vehicle 10. The upper case 24 covers the upper side of the battery body 22. The lower case 26 covers the lower side of the battery body 22. The upper case 24 and the lower case 26 are joined, and the battery body 22 is disposed inside them. Note that the battery 20 may also be referred to as a battery unit, a battery pack, or the like.

[0018] The vehicle 10 includes an under cover 30. The under cover 30 is disposed below the battery 20 and forms a part of the bottom surface of the vehicle. The under cover 30 includes a front cover 32 and a rear cover 34 disposed behind the front cover 32. By overlapping the rear end 32b of the front cover 32 and the front end 34f of the rear cover 34, a connection portion 38 of these covers 32, 34 is formed.

[0019] FIG. 2 is a bottom view schematically showing the bottom surface of the vehicle 10, and the front cover 32 and the rear cover 34 removed from the vehicle 10 are shown on the right side. Note that in FIG. 2, members that have little relation to the embodiment are omitted. For example, at the bottom of the vehicle 10, a tunnel portion for accommodating an exhaust pipe through which exhaust gas discharged from the engine flows is provided on the right side of the vehicle (the left side in FIG. 2) of the under cover 30.

[0020] The under cover 30 extends from near the front wheel 14 to near a little in front of the rear wheel 16 and is disposed closer to the left side of the vehicle (the right side in FIG. 2). The under cover 30 is approximately bisected in the front-rear direction and is composed of a front cover 32 and a rear cover 34. The battery 20 is disposed on the back side (the upper side of the vehicle) of the under cover 30.

[0021] The front cover 32 and the rear cover 34 are each a resin plate-like member. The vicinity of the rear end 32b of the front cover 32 has a width slightly larger than half of the vehicle width. The front cover 32 has a shape where its front part is narrower than its rear part. The rear cover 32 has a width slightly larger than half of the vehicle width and has a substantially rectangular shape.

[0022] The front cover 32 and the rear cover 34 each include a plurality of coupling portions 40 for coupling to the lower case 26 of the battery 20 (see FIG. 1). In FIG. 2, only a part of the plurality of coupling portions 40 is labeled with the reference numeral 40. The coupling portion 40 includes a circular recessed portion and a through hole provided at its center when viewed from the bottom of the vehicle. In the lower case 26 of the battery 20, a hole (not shown) is provided at a position facing the through hole of the coupling portion 40 of the front cover 32 and the rear cover 34 (hereinafter referred to as covers 32 and 34).

[0023] A clip 42 is used for coupling the covers 32 and 34 to the lower case 26. That is, the clip 42 is pushed into the through hole of the coupling portion 40 and the hole of the lower case 26 from the bottom side of the vehicle 10, and the tip of the clip 42 (the leg portion that expands by pushing in the clip 42) is engaged with the upper surface around the hole of the lower case 26, whereby the covers 32 and 34 are coupled to the lower case 26. In FIG. 2, the head of the clip 42 appearing on the bottom surface of the vehicle is indicated by black dots.

[0024] Figure 3 is a cross-sectional view taken along line A-A of Figure 2, showing the cross-section of the connection portion 38 between the front cover 32 and the rear cover 34. The front end 34f of the rear cover 34 is overlapped on the upper surface of the rear end 32b of the front cover 32. As shown in Figure 2, each of the two covers 32, 34 also has a plurality of coupling portions 40 at this overlapping portion (connection portion 38). Figure 2 shows a form in which each of the two covers 32, 34 has three coupling portions 40 at the overlapping portion. At this overlapping portion, the through holes of the coupling portion 40 of the front cover 32 and the through holes of the coupling portion 40 of the rear cover 34 are aligned, and the clip 42 is passed through these two through holes and engaged with the holes of the lower case 26.

[0025] The rear cover 34 has a protruding portion 36 (see Figure 3) that protrudes downward from the vehicle at a position adjacent to the overlapping portion (connection portion 38). Note that the protruding portion 36 is also called a bead. The protruding portion 36 is provided behind the connection portion 38. The protruding portion 36 is provided along the rear end face 32e (see Figure 3) of the front cover 32 that appears on the vehicle bottom surface.

[0026] Here, with reference to Figure 3, the height H of the protruding portion 36 and the return distance L of the protruding portion 36 are defined. The height H of the protruding portion 36 is the vertical distance from the lower surface of the front end 34f of the rear cover 34 to the lower surface of the top 37 of the protruding portion 36. The return distance L of the protruding portion 36 is the front-rear distance from the top 37 of the protruding portion 36 to the position where the height of the lower surface of the rear cover 34 does not change when going backward from there.

[0027] In this embodiment, regarding the protruding portion 36, the ratio of the height H to the return distance L is 1:2 (H:L = 1:2). That is, the return distance L of the protruding portion 36 is twice as long as the height H of the protruding portion 36.

[0028] Next, the operation and effect of the vehicle lower structure 12 described above will be described.

[0029] When the vehicle 10 reverses on a road with snow accumulation 202 (see Fig. 1), there is a risk that snow may enter the vehicle interior through the connection part 38 in a scene where the snow accumulation 202 advances toward the end face 32e (see Fig. 3) of the cover (front cover 32) below the connection part 38 that appears on the bottom surface of the vehicle (the scene where the snow accumulation advances from right to left in Fig. 3).

[0030] However, according to the embodiment described above, when the snow accumulation 202 advances toward the end face 32e of the front cover 32, the protruding part 36 can push the snow accumulation 202 downward to prevent the snow accumulation 202 from advancing to the end face 32e of the front cover 32. Therefore, it is possible to suppress the intrusion of snow into the vehicle interior from the connection part 38 of the two covers 32 and 34. It is possible to prevent a situation where snow intrudes from the connection part 38 and accumulates on the upper surface of the front cover 32, causing the under cover 30 to be damaged due to the weight of the snow.

[0031] In the embodiment described above, as shown in Fig. 2, the protruding part 36 is not provided for the part of the connection part 38 behind the front wheel 14 and in front of the rear wheel 16. That is, the protruding part 36 is not provided in the region indicated by the reference sign NP in Fig. 2. This is because when the vehicle 10 travels on a snow-covered road, the wheels 14 and 16 step on the snow, so it is highly likely that the snow will not approach the part of the connection part 38 located between the wheels 14 and 16, and the risk of snow intrusion at that part is low. Thus, by providing the protruding part 36 to a minimum extent, it is possible to suppress the deterioration of the aerodynamic performance of the vehicle 10 due to the protruding part 36. In this embodiment, the protruding part 36 for the part of the connection part 38 located between the wheels 14 and 16 is omitted in this way, but a configuration in which the protruding part 36 is provided may also be adopted.

[0032] Also, according to the embodiment described above, as shown in Fig. 3, the height H of the protruding part 36 and the return distance L of the protruding part 36 are in a relationship of 1:2. This ratio of H and L is set in consideration of the balance between the aerodynamic performance of the vehicle 10 and the ground clearance.

[0033] Here, consider the case where L is very large compared to H, that is, the case where the rear lower surface BP (see FIG. 3) of the protrusion 36 has a very gentle slope. In this case, when the vehicle 10 is moving forward and air (see the thick arrows in FIGS. 1 and 3) flows over the protrusion 36, the air can easily flow along the rear lower surface BP of the protrusion 36, so the aerodynamic performance of the vehicle 10 can be improved. On the other hand, in this case, since the rear lower surface BP of the protrusion 36 is at a low position over a relatively long distance (length), it is a demerit from the viewpoint of ensuring the ground clearance of the vehicle 10.

[0034] Next, consider the case where H is very large compared to L, that is, the case where the rear lower surface BP (see FIG. 3) of the protrusion 36 has a very steep slope. In this case, when the vehicle 10 is moving forward and air (see the thick arrows in FIGS. 1 and 3) flows over the protrusion 36, vortices of air are generated above the rear lower surface BP of the protrusion 36, so there is a problem that the aerodynamic performance of the vehicle 10 deteriorates. On the other hand, in this case, the rear lower surface BP of the protrusion 36 is at a low position for only a relatively short distance (length) and then is at a high position, so there is an advantage that a larger area with a high ground clearance can be ensured (it is an advantage from the viewpoint of ensuring the ground clearance of the vehicle 10).

[0035] According to the embodiment described above, by setting H:L = 1:2, the aerodynamic performance and the ground clearance can be ensured with an appropriate balance. That is, by setting this ratio of H:L, the air can flow along the rear lower surface BP of the protrusion 36, suppressing the turbulence of the air flowing under the vehicle bottom surface, and at the same time, L becomes a relatively short distance, ensuring a ground clearance with running performance. This ratio of H:L was derived through the inventor's verification.

[0036] Here, the comparative technology will be described. FIG. 5 is a cross-sectional view schematically showing a vehicle lower structure 112 according to the comparative technology. This vehicle lower structure 112 (FIG. 5) has a different structure of the connection portion 138 of the under cover 130 compared to the vehicle lower structure 12 (FIG. 1) described above.

[0037] Specifically, in the vehicle lower structure 112 of FIG. 5, the rear end 132b of the front cover 132 is bent upward toward the rear and then horizontally. Also, the front end 134f of the rear cover 134 is bent upward toward the front and then horizontally. Then, the horizontal portion of the front end 134f of the rear cover 134 is overlapped on the upper surface of the horizontal portion of the rear end 132b of the front cover 132, thereby forming the connection portion 138 between the front cover 132 and the rear cover 134. This connection portion 138 has a recessed portion 137.

[0038] In this comparative technique, when the vehicle reverses and the accumulated snow 202 advances toward the connection portion 138, the presence of the recessed portion 137 can prevent the accumulated snow 202 from advancing to the end face of the rear end 132b of the front cover 132. Therefore, it is possible to suppress the intrusion of snow from the connection portion 138 (the overlapping portion) into the vehicle interior.

[0039] Here, the advantages of the above-described embodiment (FIG. 1) over the comparative technique (FIG. 5) will be described. In the comparative technique, when the vehicle moves forward and air (see the thick arrow in FIG. 5) flows along the vehicle bottom surface, the flow of the air is disturbed at the recessed portion 137 (see the two opposing curved arrows in FIG. 5), so the aerodynamic performance deteriorates. On the other hand, according to the above-described embodiment (FIG. 1), since it has a structure with the protrusion 36 that can suppress the disturbance of the air as described above, an improvement in the aerodynamic performance can be expected compared to the comparative technique. An improvement in vehicle stability and fuel consumption (or electricity cost) can be expected.

[0040] In the comparative technology, as shown in FIG. 5, since the structure is provided with the recessed portion 137, the lower surface (referred to as the general surface) of the under cover 130 other than the recessed portion 137 is at a relatively low position. That is, the gap S between the lower case 26 of the battery 20 and the under cover 130 becomes relatively large. On the other hand, according to the embodiment described above, as shown in FIG. 1, since the structure is provided with the protruding portion 36, the position of the lower surface (general surface) of the under cover 30 other than the protruding portion 36 can be made relatively high. That is, the gap S between the lower case 26 of the battery 20 and the under cover 30 can be made relatively small.

[0041] The fact that the gap S can be reduced in the vehicle 10 has a great advantage. That is, at least one of the following (1) to (3) can be realized by the amount by which the gap S is small. (1) It is possible to set the ground clearance while ensuring running performance (the ground clearance can be increased). (2) The size of the battery 20 can be increased. (3) The interior space can be increased (a low floor can be realized).

[0042] From the above, it can be understood that the vehicle lower structure 12 (FIG. 1) of the embodiment has excellent operational effects.

[0043] Next, a modified example of the present invention will be described. FIG. 4 is an enlarged cross-sectional view of the connection portion 38 between the front cover 32 and the rear cover 34 in the modified example, showing a portion corresponding to FIG. 3. In this modified example, the structure of the connection portion 38 of the under cover 30A is different from the vehicle lower structure 12 (FIG. 1) described above.

[0044] Specifically, in this modified example, the connection portion 38 of the covers 32 and 34 is formed by overlapping the rear end 32b of the front cover 32 on the upper surface of the front end 34f of the rear cover 34. And the front cover 32 has a protruding portion 36A protruding downward from the vehicle at a position adjacent to the connection portion 38 (the overlapping portion). The protruding portion 36A is provided in front of the connection portion 38.

[0045] In this modification, as the vehicle 10 travels forward on a snow-covered road, there is a risk that snow will enter the vehicle interior through the connection part 38 in a situation where snow advances toward the end face 34e of the cover (rear cover 34) below the connection part 38 that appears on the vehicle bottom surface (a situation where snow advances from left to right in FIG. 4).

[0046] However, according to this modification, when snow advances toward the end face 34e of the rear cover 34, the protruding part 36A can push the snow downward and prevent the snow from advancing to the end face 34e of the rear cover 34. Therefore, it is possible to suppress the entry of snow into the vehicle interior from the connection part 38 of the two covers 32 and 34.

[0047] Also, according to this modification, the other operational effects of the vehicle lower structure 12 (FIG. 1) described above (such as improvement in aerodynamic performance and reduction of the gap S) can be obtained in the same manner.

[0048] In the embodiments and modifications described above, the connection part 38 of the covers 32 and 34 is formed by overlapping the rear end 32b of the front cover 32 and the front end 34f of the rear cover 34. And the cover located on the upper side at the connection part 38 among the front cover 32 and the rear cover 34 has a protruding part 36 (36A) protruding downward of the vehicle at a position adjacent to the connection part 38. With this configuration, as the vehicle 10 travels, when snow moves in the direction from the cover located on the upper side at the connection part 38 to the cover located on the lower side among the front cover 32 and the rear cover 34, the protruding part 36 (36A) can push the snow downward and prevent the snow from advancing to the end face of the lower cover that appears on the vehicle bottom surface. Therefore, it is possible to suppress the entry of snow into the vehicle interior from the overlapping part (connection part 38) of the two covers 32 and 34.

[0049] In the embodiments and modifications described above, the under cover 30 is made of resin, but the under cover 30 may be formed of other materials such as metal. Further, the under cover 30 and the lower case 26 of the battery 20 may be coupled by means other than the clip 42 (for example, screws, bolts, rivets, etc.).

Explanation of Reference Numerals

[0050] 10 Vehicle, 12 Vehicle lower structure, 14 Front wheel (wheel), 16 Rear wheel (wheel), 18 Floor panel, 20 Battery, 22 Battery body, 24 Upper case, 26 Lower case, 30, 30A Under cover, 32 Front cover (cover), 32b Rear end, 32e End face, 34 Rear cover (cover), 34f Front end, 34e End face, 36, 36A Projection (bead), 37 Top, 38 Connection part, 40 Coupling part, 42 Clip, 112 Vehicle lower structure, 130 Under cover, 132 Front cover (cover), 132b Rear end, 134 Rear cover (cover), 134f Front end, 137 Concave part, 138 Connection part, 200 Ground, 202 Snow accumulation.

Claims

1. A vehicle underbody structure applied to a vehicle with a battery mounted under the floor, comprising an under cover disposed below the battery and forming at least a part of the vehicle bottom surface, wherein the under cover includes a front cover and a rear cover disposed behind the front cover of the vehicle, a connection portion of the covers is formed by overlapping the rear end of the front cover and the front end of the rear cover, and the cover positioned above at the connection portion among the front cover and the rear cover has a protruding portion protruding downward of the vehicle at a position adjacent to the connection portion. Vehicle underbody structure.

2. The vehicle underbody structure according to Claim 1, wherein at the connection portion, the front end of the rear cover is positioned above the rear end of the front cover, and the rear cover has the protruding portion behind the connection portion of the vehicle. Vehicle underbody structure.

3. The vehicle underbody structure according to Claim 2, wherein a distance in the vehicle vertical direction from the lower surface of the front end of the rear cover to the upper and lower surfaces of the top of the protruding portion of the rear cover is defined as the height of the protruding portion, and a distance in the vehicle front-rear direction from the top of the protruding portion of the rear cover to a position where the lower surface height of the rear cover does not change toward the rear of the vehicle from there is defined as the return distance of the protruding portion, and the return distance of the protruding portion is twice as long as the height of the protruding portion. Vehicle underbody structure.

4. The vehicle underbody structure according to Claim 1, wherein at the connection portion, the rear end of the front cover is positioned above the front end of the rear cover, and the front cover has the protruding portion in front of the connection portion of the vehicle. Vehicle underbody structure.

Images