Vehicle Battery Pack Structure

Abstract

To inhibit a liquid from directly spilling on a connection part between an upper case and a lower case.SOLUTION: A vehicular battery pack structure includes a cover member which is attached to at least a part of an outer peripheral edge part of an upper case and has an outer edge part located at the outer side in a horizontal direction relative to a side surface of a lower case. The outer edge part of the cover member is formed with a lower wall part extending toward the side surface of the lower case. The side surface of the lower case is formed with a protruding wall part which protrudes from an area above the lower wall part and whose tip part is located at the outer side in the horizontal direction relative to a tip part of the lower wall part. The outer peripheral edge part of the upper case or the cover member is formed with a vertical wall part which extends in a vertical direction in a position at the inner side in the horizontal direction relative to the tip part of the protruding wall part and whose lower end part is located at a position lower than an upper end part of a side wall of the lower case.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a vehicle battery pack structure.

Background Art

[0002] The following Patent Document 1 discloses a tray constituting a battery pack mounted on an electric vehicle, in which a water receiving portion partitioned from a mounting portion for mounting a battery using ribs formed at the bottom of the tray is provided in contact with the side wall of the tray, and a gasket joint is arranged at a groove portion of the side wall of the tray in contact with the water receiving portion.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a vehicle battery pack, when washing the vehicle with a high-pressure car washer or when the vehicle travels on a wet road surface, water or liquid such as a cleaning liquid with high dynamic water pressure is injected toward the connection portion between the upper case and the lower case of the vehicle battery pack, and there is a risk that the liquid directly hits the connection portion.

[0005] An object of the present invention is to suppress the liquid from directly hitting the connection portion between the upper case and the lower case.

Means for Solving the Problems

[0006] The vehicle battery pack structure according to one aspect of the present invention includes a cover member that is attached to at least a part of the outer peripheral edge of the upper case and has an outer edge portion located horizontally outward from the side surface of the lower case. A lower wall portion extending toward the side surface of the lower case is formed at the outer edge portion of the cover member. A convex wall portion that protrudes from a region above the lower wall portion and has a tip end located horizontally outward from the tip end of the lower wall portion is formed on the side surface of the lower case. A vertical wall portion that extends in the vertical direction at a position horizontally inward from the tip end of the convex wall portion and has a lower end located lower than the upper end of the side wall of the lower case is formed on the outer peripheral edge of the upper case or the cover member.

Effect of the Invention

[0007] According to the present invention, it is possible to suppress liquid from directly hitting the connection portion between the upper case and the lower case.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

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Figure 6

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Figure 8

Figure 9

MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, with reference to the drawings, the vehicle battery pack structure according to the embodiment will be described. In each figure, FR and RR indicate the front and rear in the vehicle longitudinal direction, LH and RH indicate the left and right in the vehicle width direction, and UP and DN indicate the upper and lower in the vehicle vertical direction, respectively. Also, the vehicle center side in the vehicle width direction is referred to as the inner side in the vehicle width direction, and the side opposite to the inner side in the vehicle width direction is referred to as the outer side in the vehicle width direction. In each figure, the inner side in the vehicle width direction is indicated by IS, and the outer side in the vehicle width direction is indicated by OS. In the following description, the front and rear in the vehicle longitudinal direction, and the upper and lower in the vehicle vertical direction are simply referred to as "vehicle front", "vehicle rear", "upper", and "lower", respectively. Note that elements having the same function are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] The vehicle battery pack structure according to the embodiment is used for a vehicle battery pack 1 that supplies driving power to a vehicle V, which is an electric vehicle driven by an electric motor (not shown), as exemplified in FIGS. 1 and 2. In the illustrated example, the vehicle battery pack 1 is disposed below the vehicle V.

[0011] As shown in FIGS. 3 to 6, the vehicle battery pack 1 has a housing 5 as an exterior member that houses a battery module (not shown). The housing 5 has a hollow rectangular box shape and houses a battery module incorporating one or more single cells inside. The illustrated housing 5 has an overall flat shape in which the dimension in the vehicle up-and-down direction is smaller than the dimension in the vehicle front-rear direction or the vehicle width direction. Note that the shape of the housing 5 can be appropriately set according to the shape, dimensions of the vehicle battery pack 1, or the arrangement method in the vehicle. Note that the housing 5 may house accessories (not shown) such as a controller, a switch, and a relay that manage the capacity, voltage, temperature, etc. of the battery module.

[0012] The housing 5 includes an upper case 6 and a lower case 10. The vehicle battery pack 1 may be fastened to a vehicle body frame member (not shown) such as a side member or a cross member by a fastening tool such as a bolt (not shown) via a fixing tool such as a bracket provided at the peripheral edge of the housing 5, and fixed in the vehicle V.

[0013] The lower case 10 is a member configured to be able to accommodate battery cells. The lower case 10 is a bottomed box-shaped member with an open top, has a substantially rectangular shape in plan view, and is made of, for example, aluminum. Side walls 11 that horizontally partition the outside of the lower case 10 and the inside capable of accommodating battery cells and the like are erected at the peripheral edge of the lower case 10. The side surface of the housing 5 is constituted by the side surface 12 on the outer side in the horizontal direction of the side wall 11. Further, the side surface 12 of the lower case 10 is provided with a convex wall portion 13 described later.

[0014] One or more battery modules can be arranged at the bottom of the lower case 10. In the region on the rear side of the vehicle of the lower case 10, two or more battery modules may be stacked vertically. Note that wiring members such as bus bars (not shown) that electrically connect the plurality of battery modules to each other are arranged between the plurality of battery modules.

[0015] The upper case 6 is a plate-shaped member having a substantially rectangular shape in plan view and is made of, for example, iron. Note that the upper case 6 may be subjected to rust prevention treatment using a method such as cationic electrodeposition coating. Further, a vertical wall portion 8 described later is formed at the outer peripheral edge portion 7 of the upper case 6.

[0016] The upper case 6 is disposed so as to cover the lower case 10 from above. By closing the opening above the lower case 10 with the upper case 6, the inside of the housing 5 is sealed. As shown in FIGS. 7 and 8, the outer peripheral edge portion 7 of the upper case 6 and the upper end portion 11a of the side wall 11 of the lower case 10 are fastened by bolts 16, whereby the upper case 6 and the lower case 10 are connected to form a connection portion 15. The connection portion 15 is a gap formed between the upper case 6 and the upper end portion 11a of the lower case 10 and may include a seal member 17 described later.

[0017] In the illustrated example, a plurality of screw holes 11b extending downward are provided at predetermined intervals at the upper end portion of the side wall 11 of the lower case 10. Through holes 7a penetrating in the vertical direction are provided at positions corresponding to the screw holes 11b at the outer peripheral edge portion 7 of the upper case 6. By screwing bolts 16 into the screw holes 11b from above through the through holes 7a, the upper case 6 and the lower case 10 are connected. In the illustrated example, a separate member having screw holes 11b is disposed on the hollow side wall 11, but screw holes 11b may be directly formed in the solid side wall 11.

[0018] A connection portion 15 may be configured by interposing a seal member 17 made of a rubber material or the like between the upper case 6 and the lower case 10. In the illustrated example, a seal member 17a extending along the upper surface of the side wall 11 of the lower case 10 and a seal member 17b disposed on the inner side in the horizontal direction of the seal member 17a are interposed in the connection portion 15.

[0019] Note that, as illustrated in FIGS. 3 to 6, in the area on the vehicle rear side of the upper case 6, a bulging portion may be formed that bulges upward toward the vehicle relative to the area on the vehicle front side, according to the number of battery modules disposed in the lower case 10. As a result, more battery modules can be disposed on the vehicle rear side, and while the vehicle battery pack 1 as a whole can be made thinner and space-saving, more battery capacity can be ensured.

[0020] The cover member 20 is a member provided so as to cover at least a part of the connection portion 15 from the side of the housing 5, and is attached to at least a part of the outer peripheral edge portion 7 of the upper case 6. In the example shown in FIG. 5, the cover member 20 extends so as to cover the connection portion 15 within a predetermined range on the left side and the right side in the vehicle width direction on the vehicle front side of the housing 5, and on the left side and the right side in the vehicle width direction on the vehicle rear side. Note that the cover member 20 may be extended over the entire circumference of the outer peripheral edge portion 7 of the upper case 6.

[0021] The cover member 20 illustrated in FIGS. 7 and 8 has a substantially C-shaped cross section perpendicular to its extending direction, and includes an upper wall portion 21, side wall portions 22, and a lower wall portion 24. The cover member 20 may be made of resin, metal, or the like. By attaching the cover member 20, a space S is formed between the cover member 20 and the side surface 12 of the lower case 10.

[0022] The upper wall portion 21 is disposed on the outer peripheral edge portion 7 of the upper case 6 and extends along the outer peripheral edge portion 7 as shown in FIG. 6. Also, as shown in FIGS. 7 and 8, the upper wall portion 21 extends outward in the horizontal direction from the outer peripheral edge portion 7 of the upper case 6. Note that the inner side in the horizontal direction refers to the direction from the outside to the inside of the housing 5 in the horizontal direction, and the outer side in the horizontal direction refers to the direction opposite to the inner side in the horizontal direction. In FIGS. 7 and 8, the inner side in the vehicle width direction corresponds to the inner side in the horizontal direction, and the outer side in the vehicle width direction corresponds to the outer side in the horizontal direction.

[0023] At a position on the upper wall portion 21 corresponding to the screw hole 11b provided in the side wall 11 of the lower case 10, a through hole 21a penetrating in the vertical direction is provided. When screwing the bolt 16 into the screw hole 11b, the bolt 16 is passed through the through hole 21a, and the upper wall portion 21 is interposed between the head of the bolt 16 and the outer peripheral edge portion 7 of the upper case 6, whereby the upper wall portion 21 is clamped to both the upper case 6 and the lower case 10.

[0024] The side wall portion 22 is a wall portion extending downward from the horizontally outer edge portion of the upper wall portion 21. The lower end of the side wall portion 22 is located below a convex wall portion 13 described later. Therefore, the side wall portion 22 and the side surface 12 of the lower case 10 face each other in the horizontal direction.

[0025] Also, a portion of the cover member 20 located horizontally outward of the side surface 12 of the lower case 10 constitutes an outer edge portion 23. In other words, the cover member 20 has an outer edge portion 23 located horizontally outward of the side surface 12 of the lower case 10. In the illustrated example, the outer edge portion 23 includes a portion of the upper wall portion 21 located horizontally outward of the side surface 12 of the lower case 10, the side wall portion 22, and the lower wall portion 24.

[0026] A lower wall portion 24 extending toward the side surface 12 of the lower case 10 is formed on the outer edge portion 23 of the cover member 20. In the illustrated example, the lower wall portion 24 extends inward in the vehicle width direction from the lower end of the side wall portion 22.

[0027] The tip portion 24a located at the tip of the lower wall portion 24 in the extending direction thereof is set to be separated from the side surface 12 of the lower case 10. Therefore, a first gap 30 opening downward is formed between the side surface 12 and the tip portion 24a of the lower wall portion 24. In the illustrated example, the first gap 30 extends over the entire area between the side surface 12 and the tip portion 24a so that the side surface 12 and the tip portion 24a do not come into contact, but it is not limited thereto. The side surface 12 and the tip portion 24a of the lower wall portion 24 may be in partial contact. In an embodiment, the dimension of the first gap 30 in the width direction, which is the direction crossing the extending direction thereof, is 1 mm to 5 mm.

[0028] In addition, as shown in FIG. 6, ribs 25 may be provided in a direction crossing the extending direction of the cover member 20 above the upper wall portion 21. Further, the ribs 25 may extend in the vertical direction on the side surface of the side wall portion 22 opposite to the housing 5. By providing the ribs 25, the rigidity of the cover member 20 can be increased, and deformation of the cover member 20 due to an external force being input can be suppressed. The arrangement position of the ribs 25 can be appropriately set according to the shape of the vehicle battery pack 1, the mounting method with respect to the vehicle V, the positional relationship with the members arranged around the vehicle battery pack 1, and the like.

[0029] As shown in FIGS. 7 and 8, the convex wall portion 13 is formed so as to protrude outward in the horizontal direction from a region above the lower wall portion 24 on the side surface 12 of the lower case 10. In the illustrated example, the convex wall portion 13 extends from the upper region 12a, which is a region extending above the lower wall portion 24, of the side surface 12 of the lower case 10 toward the side wall portion 22 of the cover member 20. Further, although the convex wall portion 13 and the lower wall portion 24 are spaced apart so as not to come into contact with each other, the present invention is not limited thereto. The convex wall portion 13 and the lower wall portion 24 may be in partial contact with each other.

[0030] The tip portion 13a of the convex wall portion 13 is located outward in the horizontal direction from the tip portion 24a of the lower wall portion 24. In the illustrated example, the tip portion 13a is located outward in the vehicle width direction from the tip portion 24a. Therefore, the convex wall portion 13 and the lower wall portion 24 are arranged so as to overlap at least partially in plan view.

[0031] The tip portion 13a of the convex wall portion 13, which is located at the tip in the extending direction thereof, is set to be separated from the side wall portion 22 of the cover member 20. Therefore, a second gap 35 that opens downward is formed between the cover member 20 and the tip portion 13a of the convex wall portion 13. In the illustrated example, the second gap 35 extends over the entire area between the side wall portion 22 and the tip portion 13a of the convex wall portion 13 so that the side wall portion 22 and the tip portion 13a do not come into contact with each other, but the present invention is not limited thereto. The side wall portion 22 and the tip portion 13a of the convex wall portion 13 may be partially in contact. In a certain embodiment, the dimension of the second gap 35 in the width direction, which is the direction crossing the extending direction thereof, is 1 mm to 5 mm.

[0032] In the illustrated example, the vertical wall portion 8 is formed by bending the outer peripheral edge portion 7 of the upper case 6 downward, and extends from the outer peripheral edge portion 7 toward the convex wall portion 13. Further, the vertical wall portion 8 extends downward along the side surface 12 of the lower case 10 inward in the vehicle width direction from the tip portion 13a of the convex wall portion 13. That is, the vertical wall portion 8 extends downward along the side surface 12 of the lower case 10 at a position inward in the horizontal direction from the tip portion 13a of the convex wall portion 13. Note that the vertical wall portion 8 may extend downward at a position outward in the horizontal direction from the side surface 12 of the lower case 10. In that case, a gap is formed between the vertical wall portion 8 and the side surface 12 of the lower case 10 so as to be separated by a predetermined distance.

[0033] The lower end portion 8a of the vertical wall portion 8 is located at a position lower than the upper end portion 11a of the side wall 11 of the lower case 10. Further, the lower end portion 8a and the convex wall portion 13 face each other in the vertical direction with a third gap 40 interposed therebetween. Note that the third gap 40 may extend over the entire area between the lower end portion 8a and the convex wall portion 13. In other words, the lower end portion 8a of the vertical wall portion 8 and the convex wall portion 13 may be arranged to be separated from each other so as to be in a non-contact state. In a certain embodiment, the dimension of the third gap 40 in the width direction, which is the direction crossing the extending direction thereof, is 1 mm to 5 mm.

[0034] The configuration of the vertical wall portion 8 is not limited to the illustrated example. For example, a vertical wall portion 8 that extends downward may be formed in a region of the upper wall portion 21 of the cover member 20 that is outward in the vehicle width direction from the outer peripheral edge portion 7 of the upper case 6. In other words, the vertical wall portion 8 is formed so as to extend in the vertical direction at a position inward in the horizontal direction from the tip portion 13a of the convex wall portion 13 with respect to the outer peripheral edge portion 7 of the upper case 6 or the cover member 20.

[0035] In a certain embodiment, the vertical wall portion 8 is formed by bending downward the outer peripheral edge portion of the iron upper case 6, and the convex wall portion 13 is made of aluminum. Therefore, the vertical wall portion 8 and the convex wall portion 13 are made of different metals from each other. Even in such a case, since the lower end portion 8a of the vertical wall portion 8 and the convex wall portion 13 are separated and in a non-contact state, it is possible to suppress dissimilar metal contact corrosion caused by the difference in the natural potential between them.

[0036] Hereinafter, the operation and effects of the vehicle battery pack structure according to the embodiment will be described.

[0037] (1) The vehicle battery pack structure according to the embodiment includes a lower case 10 capable of accommodating battery cells, an upper case 6 disposed so as to cover the lower case 10 from above, and a cover member 20 attached to at least a part of the outer peripheral edge portion 7 of the upper case 6 and having an outer edge portion 23 located outward in the horizontal direction from the side surface 12 of the lower case 10. A lower wall portion 24 that extends toward the side surface 12 of the lower case 10 is formed on the outer edge portion 23 of the cover member 20, and a convex wall portion 13 that protrudes from a region above the lower wall portion 24 and has a tip portion 13a located outward in the horizontal direction from the tip portion 24a of the lower wall portion 24 is formed on the side surface 12 of the lower case 10. A vertical wall portion 8 that extends in the vertical direction at a position inward in the horizontal direction from the tip portion 13a of the convex wall portion 13 and has a lower end portion 8a located at a position lower than the upper end portion 11a of the side wall 11 of the lower case 10 is formed on the outer peripheral edge portion 7 of the upper case 6 or the cover member 20.

[0038] For example, as shown in FIG. 9, when the vehicle V travels on a wet road surface G, liquids such as water with high hydrodynamic pressure may be injected toward the vehicle battery pack 1 from around the wheels W of the vehicle V as indicated by arrows D to F. And the liquid may splash on the side or below of the vehicle battery pack 1. Similarly, when the vehicle V is washed using a high-pressure car washer, there is also a possibility that liquids such as water with high hydrodynamic pressure or cleaning liquid may splash on the vehicle battery pack 1. And a part of the liquid will be incident toward the connection part 15 where the upper case 6 and the lower case 10 are connected. Even in such a case, according to the vehicle battery pack structure according to the embodiment, the liquid injected toward the connection part 15 can be shielded by the cover member 20. Further, even if a liquid with high hydrodynamic pressure is incident toward the first gap 30 formed between the lower wall part 24 of the cover member 20 and the side surface 12 of the lower case 10, it is shielded by the convex wall part 13 and the vertical wall part 8, and it is possible to suppress the liquid from directly splashing on the connection part 15. That is, according to the vehicle battery pack structure according to the embodiment, it is possible to suppress the liquid from directly splashing on the connection part 15 between the upper case 6 and the lower case 10.

[0039] (2) In the vehicle battery pack structure according to the embodiment, a first gap 30 that opens downward is formed between the side surface 12 of the lower case 10 and the tip part 24a of the lower wall part 24, and a second gap 35 that opens downward is formed between the cover member 20 and the tip part 13a of the convex wall part 13.

[0040] According to the vehicle battery pack structure according to the embodiment, even when water or a liquid such as a cleaning liquid enters the space S via the gap between the cover member 20 and the upper surface of the upper case 6 when the vehicle is being washed or when the vehicle V travels on a wet road surface, as shown by the arrow C in FIGS. 7 and 8, the liquid is discharged to the outside of the space S via the second gap 35 or the first gap 30. That is, according to the vehicle battery pack structure according to the embodiment, the liquid that has entered the space S can be discharged from the first gap 30.

[0041] (3) In the vehicle battery pack structure according to the embodiment, the vertical wall portion 8 and the convex wall portion 13 are made of different metals, and the lower end portion 8a of the vertical wall portion 8 and the convex wall portion 13 are spaced apart so as to be in a non-contact state.

[0042] According to the vehicle battery pack structure according to the embodiment, a third gap 40 is interposed between the vertical wall portion 8 and the convex wall portion 13, and the two do not come into contact with each other. Therefore, even when liquid enters the space S, it is possible to suppress the vertical wall portion 8 and the convex wall portion 13 from being electrically connected through the liquid. Therefore, it is possible to suppress the occurrence of dissimilar metal contact corrosion caused by the different natural potentials of the two when the vertical wall portion 8 and the convex wall portion 13 are made of different metals.

[0043] In the above embodiment, an electric vehicle has been described as an example. However, it goes without saying that the vehicle battery pack structure according to the embodiment can also be applied to a vehicle battery pack that supplies driving power for a hybrid vehicle.

Explanation of reference numerals

[0044] 1 Vehicle battery pack 6 Upper case 7 Outer peripheral edge 8 Vertical wall portion 8a Lower end portion 10 Lower case 11 Side wall 11a Upper end portion 12 Side surface 12a Upper region 13 Convex wall portion 13a Tip portion 20 Cover member 23 Outer edge 24 Lower wall portion 24a Tip portion 30 First gap 35 Second gap

Claims

1. A lower case capable of accommodating a battery cell, an upper case disposed so as to cover the lower case from above, a cover member attached to at least a part of the outer peripheral edge of the upper case and having an outer edge portion located horizontally outward from the side surface of the lower case, comprising: a lower wall portion extending toward the side surface of the lower case is formed on the outer edge portion of the cover member, a convex wall portion protruding from a region above the lower wall portion is formed on the side surface of the lower case, and a tip end portion of the convex wall portion is located horizontally outward from a tip end portion of the lower wall portion, a vertical wall portion extending in the vertical direction at a position horizontally inward from the tip end portion of the convex wall portion is formed on the outer peripheral edge of the upper case or the cover member, and a lower end portion of the vertical wall portion is located at a position lower than an upper end portion of the side wall of the lower case, A vehicle battery pack structure.

2. A first gap opening downward is formed between the side surface of the lower case and the tip end portion of the lower wall portion, A second gap opening downward is formed between the cover member and the tip end portion of the convex wall portion. The vehicle battery pack structure according to claim 1.

3. The vertical wall portion and the convex wall portion are made of different metals, The lower end portion of the vertical wall portion and the convex wall portion are separated from each other so as to be in a non-contact state. The vehicle battery pack structure according to claim 1 or 2.

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