Vehicle undercarriage

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 lower structure, and particularly to a vehicle lower structure applied to a vehicle having a battery mounted under the vehicle floor. [[Background Art]]

[0002] Conventionally, electric vehicles such as battery electric vehicles (BEV), hybrid vehicles (HEV), and plug-in hybrid vehicles (PHEV) have been known. An electric vehicle includes a battery that supplies electric power to a drive motor. Some electric vehicles have a battery disposed under the vehicle floor. An undercover that forms at least a part of the vehicle bottom surface is provided on the lower side of the battery.

[0003] Patent Document 1 discloses an underfloor structure for an electric vehicle in which a battery unit installed under the vehicle floor is covered by a battery undercover. [[Prior Art Documents]] [[Patent Documents]]

[0004] [[Patent Document 1]] Japanese Patent Laid-Open No. 2011-219042 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0005] The undercover may be constituted by a plurality of covers. The undercover includes a front cover and a rear cover disposed rearward of the front cover in the vehicle, and a connecting portion between the covers is formed by overlapping the rear end of the front cover and the front end of the rear cover.

[0006] In a vehicle provided with such an undercover, when the vehicle travels on a snow-covered road, there is a risk that snow may invade the inside of the vehicle from the overlapping portion (connecting portion) of the front cover and the rear cover. Accordingly, there is a demand for a structure capable of suppressing snow intrusion from the overlapping portion (connecting portion) of the two covers.

[0007] The object of the present invention is to provide a vehicle understructure that can prevent snow from entering through the connection point between two covers located at the bottom of the vehicle. [Means for solving the problem]

[0008] The vehicle understructure according to the present invention is a vehicle understructure applicable to a vehicle in which a battery is mounted under the floor, and comprises an under cover positioned below the battery and forming at least a part of the vehicle bottom surface, the under cover including a front cover and a rear cover positioned behind the front cover, the rear end of the front cover On the upper side Front end of the aforementioned rear cover of By overlapping them, the connection points of those covers are formed. The aforementioned rear cover This is a position adjacent to the aforementioned connection part. and the rear of the vehicle of the connection part It has a protruding part that extends downwards towards the vehicle. The rear cover has a base adjacent to the protrusion and located behind the protrusion at the vehicle rear, and the rear cover is configured such that the front lower surface and the base upper surface are aligned in the vehicle vertical direction, and the protrusion includes a front lower surface from the front end of the rear cover to the top of the protrusion and a rear lower surface from the top of the protrusion to the base of the rear cover, and the front lower surface of the protrusion has a steeper inclination than the rear lower surface of the protrusion. It is characterized by the following:

[0010] Furthermore, in the vehicle understructure according to the present invention, the distance in the vehicle's vertical direction from the front end lower surface of the rear cover to the top upper surface of the protrusion of the rear cover is defined as the height of the protrusion, and the distance in the vehicle's longitudinal direction from the top of the protrusion of the rear cover to a position toward the rear of the vehicle where the height of the lower surface of the rear cover no longer changes is defined as the return distance of the protrusion, and the return distance of the protrusion may be twice the height of the protrusion. [Effects of the Invention]

[0012] According to the present invention, when snow moves from the upper cover at the connection point between the front and rear covers as the vehicle is in motion toward the lower cover, the protruding part pushes the snow downwards, preventing the snow from advancing toward the end face of the lower cover that is exposed on the underside of the vehicle. Therefore, it is possible to suppress snow from entering the vehicle through the overlapping portion (connection point) of the two covers. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view showing the undercarriage of the vehicle. [Figure 2] This is a bottom view diagram illustrating the underside of the vehicle. [Figure 3] This is a magnified cross-sectional view of the connection point of the underbody cover. [Figure 4] Enlarged cross-sectional view of the under cover connection in a modified example. [Figure 5] This is a schematic cross-sectional view showing the vehicle understructure related to the comparative technology. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiments described herein. In all drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted. In the following description, unless otherwise specified, terms indicating directions and orientations such as front, back, left, right, up, and down refer to directions and orientations related to the vehicle. In each figure, the arrow FR indicates the front, the arrow UP indicates upward, and the arrow RH indicates rightward.

[0015] Figure 1 is a schematic cross-sectional view of the vehicle understructure 12, with the entire vehicle 10 schematically shown at the top. The lower part of the figure shows an enlarged cross-section of the portion of the vehicle 10 enclosed by the dashed line at the top (the underside of the vehicle between the front wheels 14 and the rear wheels 16), which is the vehicle understructure 12. The ground 200 and snow cover 202 are also shown in Figure 1.

[0016] Vehicle 10 is a plug-in hybrid vehicle (PHEV) and is an automobile. Vehicle 10 may also be other electric vehicles such as a battery electric vehicle (BEV) or a hybrid electric vehicle (HEV). Vehicle 10 has a battery 20 mounted under the floor. That is, the battery 20 is located beneath the vehicle's floor panel 18. The area above the floor panel 18 is the passenger compartment.

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

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

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

[0020] The undercover 30 extends from the vicinity of front wheels 14 to a position slightly forward of rear wheels 16, and is disposed closer to the vehicle left side (the right side in FIG. 2). The undercover 30 is roughly divided into two equal parts in the front-rear direction, and is configured of the front cover 32 and the rear cover 34. The battery 20 is disposed on the back side (vehicle upper side) of the undercover 30.

[0021] The front cover 32 and the rear cover 34 are each plate-shaped members made of resin. The vicinity of the rear end 32b of the front cover 32 has a width slightly larger than half the vehicle width. The front cover 32 has a shape where the front portion is narrower than the rear portion. The rear cover 34 has a width slightly larger than half 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 a lower case 26 of a battery 20 (see FIG. 1). In FIG. 2, reference numeral 40 is assigned to only some of the plurality of coupling portions 40. The coupling portion 40 includes a circular recessed portion and a through hole provided at the center thereof when viewed from the vehicle bottom surface. In the lower case 26 of the battery 20, a hole (not illustrated) 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] Clips 42 are used for coupling the covers 32, 34 to the lower case 26. Specifically, the clip 42 is pushed from the bottom side of the vehicle 10 into the through hole of the coupling portion 40 and the hole of the lower case 26, and the tip end of the clip 42 (the leg portion that expands when the clip 42 is pushed) is engaged with the upper surface around the hole of the lower case 26, whereby the covers 32, 34 are coupled to the lower case 26. In FIG. 2, the head of the clip 42 exposed on the vehicle bottom surface is indicated by a black dot.

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

[0025] The rear cover 34 has a projection 36 (see Figure 3) that protrudes downward from the vehicle, adjacent to the overlapping portion (connecting portion 38). The projection 36 is also called a bead. The projection 36 is located behind the connecting portion 38. The projection 36 is located along the rear end face 32e (see Figure 3) of the front cover 32, which is visible on the underside of the vehicle.

[0026] Here, referring to Figure 3, we define the height H of the protrusion 36 and the return distance L of the protrusion 36. The height H of the protrusion 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 protrusion 36. The return distance L of the protrusion 36 is the front-rear distance from the top 37 of the protrusion 36 to the position where the height of the lower surface of the rear cover 34 no longer changes, moving backward from there.

[0027] In this embodiment, with respect to the protrusion 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 protrusion 36 is twice the length of the height H of the protrusion 36.

[0028] Next, we will explain the effects and benefits of the vehicle understructure 12 described above.

[0029] When vehicle 10 is driving in reverse on a road with snow accumulation 202 (see Figure 1), there is a risk that the snow accumulation 202 will advance towards the end face 32e (see Figure 3) of the lower cover (front cover 32) of the connection part 38, which is exposed on the underside of the vehicle (as shown in Figure 3, where the snow is advancing from right to left), and that the snow may enter the interior of the vehicle through the connection part 38 (overlapping portion).

[0030] However, according to the embodiment described above, when snow 202 advances toward the end face 32e of the front cover 32, the protrusion 36 pushes the snow 202 downward, preventing it from advancing toward the end face 32e of the front cover 32. Therefore, it is possible to prevent snow from entering the vehicle interior through the connection portion 38 of the two covers 32 and 34. This prevents snow from entering through the connection portion 38 and accumulating on the upper surface of the front cover 32, which could damage the under cover 30 due to the weight of the snow.

[0031] In the embodiment described above, as shown in Figure 2, no protrusions 36 are provided on the connecting portion 38 behind the front wheel 14 and in front of the rear wheel 16. That is, no protrusions 36 are provided in the region indicated by the symbol NP in Figure 2. This is because when the vehicle 10 travels on a snow-covered road, the wheels 14 and 16 trample the snow, so it is unlikely that snow will approach the connecting portion 38 located between the wheels 14 and 16, thus reducing the risk of snow intrusion in that area. By providing the protrusions 36 to a minimum, the deterioration of the aerodynamic performance of the vehicle 10 due to the protrusions 36 can be suppressed. In this embodiment, the protrusions 36 are omitted on the connecting portion 38 located between the wheels 14 and 16, but a configuration in which such protrusions 36 are provided is also possible.

[0032] Furthermore, according to the embodiment described above, as shown in Figure 3, the height H of the protrusion 36 and the return distance L of the protrusion 36 are in a 1:2 relationship. This ratio of H to L was set considering the balance between the aerodynamic performance and ground clearance of the vehicle 10.

[0033] Now, consider the case where L is very large compared to H, that is, the case where the rear lower surface BP of the protrusion 36 (see Figure 3) has a very gentle slope. In this case, when the vehicle 10 is traveling forward and air (see the thick arrows in Figures 1 and 3) flows over the protrusion 36, the air is more likely to flow along the rear lower surface BP of the protrusion 36, thus improving the aerodynamic performance of the vehicle 10. On the other hand, in this case, the rear lower surface BP of the protrusion 36 is low over a relatively long distance (length), which is a disadvantage from the standpoint of ensuring the ground clearance of the vehicle 10.

[0034] Next, consider the case where H is much larger than L, that is, the case where the rear lower surface BP of the protrusion 36 (see Figure 3) has a very steep slope. In this case, when the vehicle 10 moves forward and air (see the thick arrows in Figures 1 and 3) flows over the protrusion 36, an air vortex is generated above the rear lower surface BP of the protrusion 36, which causes a problem in 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 lower for a relatively short distance (length), and the area behind it is higher, so there is an advantage in that a larger area with high ground clearance can be secured (this is an advantage from the perspective of securing the ground clearance of the vehicle 10).

[0035] According to the embodiment described above, by setting H:L = 1:2, an appropriate balance between aerodynamic performance and ground clearance can be secured. In other words, by using this H:L ratio, air flows along the rear lower surface BP of the protrusion 36, suppressing turbulence in the airflow under the vehicle, and L is made as short as possible, ensuring sufficient ground clearance for off-road driving. This H:L ratio was derived through the inventor's verification.

[0036] Now, let's explain the comparative technology. Figure 5 is a schematic cross-sectional view of a vehicle understructure 112 relating to the comparative technology. This vehicle understructure 112 (Figure 5) differs from the vehicle understructure 12 (Figure 1) described above in the structure of the connection part 138 of the under cover 130.

[0037] Specifically, in the vehicle understructure 112 shown in Figure 5, the rear end 132b of the front cover 132 is bent upward toward the rear and then bent horizontally. Similarly, the front end 134f of the rear cover 134 is bent upward toward the front and then bent horizontally. The horizontal portion of the front end 134f of the rear cover 134 is superimposed on the upper surface of the horizontal portion of the rear end 132b of the front cover 132, thereby forming a 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 technology, when the vehicle is moving in reverse, the presence of the recessed portion 137 prevents the snow 202 from advancing toward the rear end 132b of the front cover 132 as the snow 202 moves toward the connection portion 138. Therefore, it is possible to suppress snow from entering the vehicle through the connection portion 138 (overlapping portion).

[0039] Here, we will explain the advantages of the embodiment described above (Figure 1) over the comparative technology (Figure 5). In the comparative technology, when the vehicle moves forward and air (see the thick arrow in Figure 5) flows along the underside of the vehicle, the airflow is disturbed at the recessed portion 137 (see the two opposing curved arrows in Figure 5), resulting in a deterioration of aerodynamic performance. On the other hand, according to the embodiment described above (Figure 1), as described above, the structure has a protruding portion 36 that can suppress air turbulence, so an improvement in aerodynamic performance can be expected compared to the comparative technology. Improvements in vehicle stability and fuel efficiency (or electric power consumption) can be expected.

[0040] Furthermore, in the comparative technology, as shown in Figure 5, the structure has a recessed portion 137, so the lower surface (general surface) of the under cover 130 other than the recessed portion 137 is at a relatively low position. In other words, 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 Figure 1, the structure has a protruding portion 36, so the position of the lower surface (general surface) of the under cover 30 other than the protruding portion 36 can be made relatively high. In other words, the gap S between the lower case 26 of the battery 20 and the under cover 30 can be made relatively small.

[0041] Reducing the gap S in vehicle 10 offers significant advantages. In other words, by reducing the gap S, at least one of the following (1) to (3) can be achieved. (1) It is possible to set a ground clearance that ensures off-road capability (the ground clearance can be increased). (2) The size of the battery 20 can be increased. (3) The interior space can be expanded (a low floor can be achieved).

[0042] From the above, it can be understood that the vehicle understructure 12 of the embodiment (Figure 1) has excellent effects and advantages.

[0043] Next, a modified version of the present invention will be described. Figure 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 version, showing the portion corresponding to Figure 3. In this modified version, the structure of the connection portion 38 of the under cover 30A differs from that of the vehicle understructure 12 (Figure 1) described above.

[0044] Specifically, in this modified example, the rear end 32b of the front cover 32 is superimposed on the upper surface of the front end 34f of the rear cover 34, thereby forming a connection portion 38 between the covers 32 and 34. The front cover 32 has a projection 36A that protrudes downward toward the vehicle at a position adjacent to the connection portion 38 (overlapping portion). The projection 36A is provided in front of the connection portion 38.

[0045] In this modified example, as vehicle 10 travels forward on a snow-covered road, there is a risk that snow could enter the vehicle through the connection portion 38 (overlapping portion) as it advances toward the end face 34e of the lower cover (rear cover 34) of the connection portion 38, which is visible on the underside of the vehicle (as shown in Figure 4, where the snow advances from left to right).

[0046] However, with this modification, when snow accumulates towards the end face 34e of the rear cover 34, the protrusion 36A pushes the snow down, preventing it from accumulating on the end face 34e of the rear cover 34. As a result, it is possible to prevent snow from entering the vehicle through the connection 38 of the two covers 32 and 34.

[0047] Furthermore, this modified version also allows for the same other effects of the vehicle understructure 12 (Figure 1) described above (such as improved aerodynamic performance and reduced gap S).

[0048] In the embodiments and modifications described above, the rear end 32b of the front cover 32 and the front end 34f of the rear cover 34 are overlapped to form a connection portion 38 between the covers 32 and 34. The cover located on the upper side of the connection portion 38 has a projection 36 (36A) adjacent to the connection portion 38 that protrudes downward toward the vehicle. With this configuration, when the vehicle 10 is in motion, and snow moves from the cover located on the upper side of the connection portion 38 toward the cover located on the lower side, the projection 36 (36A) pushes the snow downward, preventing the snow from advancing toward the end face of the lower cover that is exposed on the underside of the vehicle. Therefore, it is possible to suppress snow from entering the vehicle through the overlapping portion (connection portion 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 made of other materials such as metal. Also, the under cover 30 and the lower case 26 of the battery 20 may be joined by means other than the clip 42 (for example, screws, bolts, rivets, etc.). [Explanation of Symbols]

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

Claims

1. A vehicle understructure applicable to a vehicle in which the battery is mounted under the floor, It is provided with an under cover located below the battery, which forms at least a portion of the vehicle's underside, The aforementioned under cover includes a front cover and a rear cover positioned behind the front cover of the vehicle. The front end of the rear cover is superimposed on the upper side of the rear end of the front cover, thereby forming a connection between the covers. The aforementioned rear cover has a projection that is adjacent to the connection portion and protrudes downward from the vehicle at the rear of the connection portion, The aforementioned rear cover has a base located adjacent to the protrusion and at the rear of the vehicle relative to the protrusion. The aforementioned rear cover is configured such that the lower front end surface and the upper base surface are aligned in the vehicle's vertical direction. The protrusion includes a front lower surface from the front end of the rear cover to the top of the protrusion, and a rear lower surface from the top of the protrusion to the base of the rear cover. The front lower surface of the protrusion has a steeper inclination than the rear lower surface of the protrusion. Vehicle understructure.

2. The vehicle understructure according to claim 1, The distance in the vehicle's vertical direction from the lower front end surface of the rear cover to the upper and lower top surfaces of the protrusion of the rear cover is defined as the height of the protrusion. The distance in the longitudinal direction of the vehicle from the top of the protrusion of the rear cover to the position toward the rear of the vehicle where the height of the lower surface of the rear cover no longer changes is defined as the return distance of the protrusion. The return distance of the protrusion is twice the height of the protrusion. Vehicle understructure.

Images