Vehicle undercarriage

Abstract

The present invention provides a vehicle understructure that can prevent liquid adhering to the top surface of the battery case from flowing to the outer periphery of the battery case and reaching the battery cells inside the battery case. [Solution] The battery case 22 has a lower case 24 having a first outer periphery 28 and an upper case 35 having a second outer periphery 39 facing the first outer periphery, and a battery cell 54 is housed inside; vehicle frame members 12 and 14 that support a part of the outer periphery; a first sealing member 60 that contacts the opposing surfaces of the first and second outer periphery; and a second sealing member 70 that contacts the outer periphery and the vehicle frame member and is located lower than the first sealing member.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 below discloses a vehicle in which an outer peripheral portion of a battery case storing battery cells is supported by a vehicle body frame member, and a seal member is provided between the outer peripheral portion of the battery case and the vehicle body frame member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a liquid such as water adhering to the upper surface of the battery case flows to the outer peripheral portion of the battery case, the outer peripheral portion may be corroded by the influence of the liquid and holes may be formed in the outer peripheral portion. In such a case, Patent Document 1 has room for improvement in preventing the liquid from reaching the battery cells in the battery case through the holes formed in the outer peripheral portion.

[0005] In consideration of the above facts, an object of the present invention is to obtain a vehicle underbody structure capable of suppressing the liquid adhering to the upper surface of the battery case from flowing to the battery cells in the battery case when the liquid flows to the outer peripheral portion of the battery case.

Means for Solving the Problems

[0006] The vehicle understructure of the first embodiment includes a battery case having a lower case having a first outer periphery that constitutes the outer periphery, and an upper case having a second outer periphery that constitutes the outer periphery and faces the first outer periphery, with a battery cell housed inside; a vehicle frame member that supports a part of the outer periphery; a first sealing member that contacts the opposing surfaces of the first outer periphery and the second outer periphery; and a second sealing member that contacts the outer periphery and the vehicle frame member and is located lower to the vehicle than the first sealing member.

[0007] In the first embodiment of the vehicle understructure, the first sealing member contacts the opposing surfaces of the first outer periphery of the lower case and the second outer periphery of the upper case. Furthermore, the second sealing member contacts the outer peripheries of the upper and lower cases with the vehicle body frame member, and the second sealing member is located lower to the vehicle than the first sealing member. Therefore, for example, if liquid adhering to the upper surface of the battery case flows to the outer periphery of the battery case, the second sealing member can store the liquid in the portion of the battery case below the first sealing member. Thus, the first embodiment of the vehicle understructure can prevent liquid adhering to the upper surface of the battery case from flowing towards the battery cells inside the battery case.

[0008] In the second embodiment, the vehicle understructure comprises, in the first embodiment, an upper portion and a lower portion located on the outer periphery and below the upper portion, wherein the first sealing member contacts the opposing surfaces of the upper portion of the first and second outer periphery, and the second sealing member contacts the lower portion of the outer periphery and the vehicle body frame member.

[0009] According to the vehicle understructure of the second embodiment, the second sealing member can be positioned lower than the first sealing member without complicating the structure of the battery case.

[0010] The vehicle understructure of the third embodiment is a joined portion in which a part of the outer periphery is joined to the vehicle body frame member, and the second sealing member is in contact with the joined portion and the vehicle body frame member.

[0011] The vehicle understructure of the third embodiment can suppress corrosion of the joined portion, which is a part of the outer circumference of the battery case and is joined to the vehicle body frame member, and the joint portion of the vehicle body frame member with the joined portion, due to liquid adhering to the battery case.

[0012] In the fourth embodiment, the vehicle understructure, in the first or second embodiment, has the upper surface of the upper case constituting the floor panel of the vehicle equipped with the vehicle body frame member.

[0013] In the fourth embodiment of the vehicle understructure, the upper surface of the upper case also serves as the vehicle's floor panel. Therefore, if, for example, liquid from a container inside the vehicle spills out of the container, this liquid may adhere to the floor panel (the upper surface of the upper case). The fourth embodiment of the vehicle understructure can prevent the liquid from moving towards the battery cells in the battery case in such cases. [Effects of the Invention]

[0014] As described above, the vehicle understructure according to the present invention has the excellent effect of being able to suppress the flow of liquid adhering to the upper surface of the battery case to the battery cells inside the battery case when the liquid flows to the outer periphery of the battery case. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic plan view showing the body frame members and battery module of a vehicle to which the vehicle understructure according to the embodiment is applied. [Figure 2] This is a schematic cross-sectional view along the arrow 2-2 in Figure 1. [Figure 3] This is an enlarged view of the front part of the cross-sectional view in Figure 2. [Figure 4] This is a magnified view similar to Figure 3, showing a through-hole formed on the outer circumference of the battery case due to corrosion. [Figure 5] This is a schematic cross-sectional view along the line 5-5 in Figure 1. [Modes for carrying out the invention]

[0016] Hereinafter, the vehicle underbody structure according to the embodiment will be described with reference to the accompanying drawings. The arrows UP, FR, and LH shown in each drawing indicate the upper side in the vehicle up-down direction, the front side in the vehicle front-rear direction, and the left side in the vehicle left-right direction, respectively.

[0017] As shown in FIGS. 1 and 2, a vehicle 10 to which the vehicle underbody structure of the present embodiment is applied includes a pair of left and right front wheels 11F, a pair of left and right rear wheels 11R, a pair of left and right rockers 12 that are part of the vehicle body frame members and extend in the vehicle front-rear direction, and a pair of front and rear cross members 14 that are part of the vehicle body frame members and extend in the vehicle width direction (left-right direction) and both ends of which are fixed to the left and right rockers 12. The rockers 12 and the cross members 14 are made of metal. As shown in FIGS. 2 and 5, the cross-sectional shapes of the rockers 12 and the cross members 14 are square.

[0018] The battery module 20 of the present embodiment has a battery case 22, a battery stack 50, and a first seal member 60.

[0019] The battery case 22 has a lower case 24 and an upper case 35. The lower case 24 and the upper case 35 are integrally formed metal products.

[0020] The lower case 24 is a hollow body having an opening 25 formed in the upper surface. The lower case 24 has a bottom plate portion 26, a peripheral wall portion 27, and a first outer peripheral portion (outer peripheral portion) 28. The planar shape of the peripheral wall portion 27 is annular, and the lower end portion of the peripheral wall portion 27 is connected to the outer peripheral edge portion of the bottom plate portion 26. The planar shape of the first outer peripheral portion 28 is annular, and the inner peripheral edge portion of the first outer peripheral portion 28 is connected to the upper end portion of the peripheral wall portion 27. As shown in FIGS. 3 and 5, the first outer peripheral portion 28 includes an upper stage portion 29 connected to the upper end portion of the peripheral wall portion 27, a hanging portion 30 extending downward from the outer peripheral edge portion of the upper stage portion 29, and a lower stage portion 31 extending substantially horizontally from the lower end portion of the hanging portion 30 toward the outer peripheral side.

[0021] The upper case 35 is a hollow body having an opening 36 formed in its lower surface. The upper case 35 has a top plate portion 37, a peripheral wall portion 38, and a second outer peripheral portion (outer peripheral portion) 39. The planar shape of the peripheral wall portion 38 is annular, and the upper end portion of the peripheral wall portion 38 is connected to the outer peripheral edge portion of the top plate portion 37. The planar shape of the second outer peripheral portion 39 is annular, and the inner peripheral edge portion of the second outer peripheral portion 39 is connected to the lower end portion of the peripheral wall portion 38. As shown in FIGS. 3 and 5, the second outer peripheral portion 39 includes an upper stage portion 40 connected to the lower end portion of the peripheral wall portion 38, a hanging portion 41 extending downward from the outer peripheral edge portion of the upper stage portion 40, and a lower stage portion 42 extending substantially horizontally from the lower end portion of the hanging portion 41 toward the outer peripheral side. The vertical dimension of the hanging portion 41 is larger than the vertical dimension of the hanging portion 30.

[0022] As shown in FIGS. 2 and 3, a battery stack 50 is provided inside the lower case 24. The battery stack 50 includes a number of battery cells 52 arranged in the front-rear direction, a number of bus bars (not shown), and a cooler (not shown).

[0023] As shown in Figures 2 and 3, the battery stack 50 is positioned in the internal space of the lower case 24, which is separated from the upper case 35, and is placed on and fixed to the bottom plate portion 26. In this state, the first sealing member 60, which is annular in shape and made of a flexible material, is placed on the entire upper surface of the upper section 29 of the first outer peripheral portion 28 of the lower case 24 (not shown in Figure 2). Furthermore, in this state, the upper case 35 is placed over the lower case 24 from above. That is, the entire lower section 42 of the second outer peripheral portion 39 is placed on the upper surface of the lower section 31 of the first outer peripheral portion 28, and the lower part of the inner surface of the hanging section 41 faces the outer surface of the hanging section 30. As a result, the first sealing member 60 is deformed between the upper surface of the upper section 29 of the first outer peripheral portion 28 and the lower surface of the upper section 40 of the second outer peripheral portion 39. In other words, the first sealing member 60 is in liquid-tight contact with the entire circumference of the upper surface of the upper section 29 and the entire circumference of the lower surface of the upper section 40. Furthermore, multiple points on the supported portions 31E and 42E, which are the outer peripheries of the lower portion 31 of the first outer periphery 28 and the lower portion 42 of the second outer periphery 39, are fixed together by multiple fixing members. These fixing members are, for example, bolts that pass through the supported portions 31E and 42E and nuts that can be screwed onto the bolts. This completes the battery module 20 in which the entire supported portion 31E and the entire supported portion 42E are in contact with each other. Even if a liquid such as water enters the gap between the supported portion 31E of the lower portion 31 of the lower case 24 and the supported portion 42E of the lower portion 42 of the upper case 35 of the battery module 20 with this configuration, the first sealing member 60 prevents this liquid from moving toward the battery stack 50.

[0024] In this configuration, the battery case 22 of the battery module 20 is supported by the rockers 12 and the cross members 14. That is, as shown in Figures 1 to 3 and Figure 5, with the top plate portion 37 and peripheral wall portion 38 of the upper case 35 located in the space surrounded by the rockers 12 and the cross members 14, the lower portion 42 of the second outer peripheral portion 39 is brought closer to the lower surfaces of each rocker 12 and each cross member 14 from below.

[0025] Furthermore, as shown in Figures 3 and 5, a second sealing member 70, which is annular in shape and made of a flexible material, is placed on the entire upper surface of the lower section 42 of the second outer peripheral portion 39 of the upper case 35 (not shown in Figure 2). The second sealing member 70 is located on the inner circumference side of the supported portions 31E and 42E. In this state, the lower surfaces of the rocker 12 and the cross member 14 and multiple points on the supported portions 31E and 42E of the lower sections 31 and 42 are fixed together by multiple fixing members. These fixing members are, for example, the bottom plate of the rocker 12, the bottom plate of the cross member 14, bolts that penetrate the supported portions 31E and 42E, and weld nuts fixed to the upper surfaces of the bottom plates of the rocker 12 and the cross member 14 that can be screwed with the bolts. These fixing members pull the first outer periphery 28 and the second outer periphery 39 upward, so that the supported portion (joined portion) 42E of the second outer periphery 39 is joined to the lower surface of each rocker 12 and each cross member 14. Furthermore, as the first outer periphery 28 and the second outer periphery 39 are pulled upward, the second sealing member 70 is deformed between the upper surface of the lower section 42 and the lower surface of the bottom plate of the rocker 12 and the cross member 14, as shown in Figures 3 and 5. In other words, the second sealing member 70 is in liquid-tight contact with the entire circumference of the upper surface of the lower section 42 and the entire circumference of the lower surface of the bottom plate of the rocker 12 and the cross member 14. Even if a liquid such as water enters the gap between the bottom plate of the rocker 12 and the cross member 14 and the supported portion 42E of the lower section 42 of the upper case 35, the second sealing member 70 prevents this liquid from moving toward the hanging portion 41.

[0026] Furthermore, the upper surface of the top plate portion 37 of the upper case 35 constitutes the floor panel of the vehicle 10. A cloth-like mat material (not shown) is placed over the upper surface of the top plate portion 37.

[0027] (Mechanism of action and effect) Next, the operation and effects of this embodiment will be described.

[0028] In the vehicle 10 of this embodiment, the first sealing member 60 is in liquid-tight contact with the opposing surfaces of the upper part 29 of the first outer peripheral portion 28 of the lower case 24 and the upper part 40 of the second outer peripheral portion 39 of the upper case 35. Furthermore, the second sealing member 70 is in liquid-tight contact with the lower part 42 of the second outer peripheral portion 39 of the upper case 35 and the lower surface of the bottom plate of the rocker 12 and the cross member 14. Moreover, the lower part 42 of the second outer peripheral portion 39 is located below the upper part 29 of the lower case 24. Therefore, the second sealing member 70 is located lower in the vehicle than the first sealing member 60. For example, if an occupant of the vehicle 10 spills liquid from a container onto the mat material inside the vehicle, this liquid W will permeate the mat material downwards and then adhere to the upper surface of the top plate portion 37 (see Figure 4). Furthermore, this liquid W may flow along the front of the peripheral wall portion 38 to the upper surface of the lower part 42.

[0029] In this case, the movement of the liquid W toward the supported portion 42E is prevented by the second sealing member 70. Therefore, the liquid W is stored in the space enclosed by the front of the second sealing member 70, the front of the lower portion 42, and the front of the hanging portion 41. In other words, there is little risk of this liquid W entering the inside of the battery case 22 and adhering to the battery cell 54.

[0030] Incidentally, if liquid W accumulates in the space for a long period of time, as shown in Figure 4, a part of the lower section 42 may corrode, and a through hole 42X may be formed in a part of the lower section 42. In this case, liquid W may enter the gap between the lower section 42 and the lower section 31 through the through hole 42X, and the liquid W may flow inward through this gap. However, the hanging part 30 of the lower case 24 is located on the inner side of this gap. Therefore, the movement of liquid W inward is prevented by the hanging part 30. In other words, there is little risk of liquid W that has entered this gap moving upward through the gap between the hanging part 30 and the hanging part 41.

[0031] Furthermore, the first sealing member 60 is in liquid-tight contact with the entire upper surface of the upper section 29 and the entire lower surface of the upper section 40. Therefore, even if the liquid W moves upward through the gap between the hanging section 30 and the hanging section 41, the risk of the liquid W passing through the gap between the upper section 29 and the upper section 40 into the battery case 22 and adhering to the battery cell 54 is extremely small.

[0032] Furthermore, the battery case 22 includes upper sections 29 and 40, and lower sections 31 and 42 located below the upper sections 29 and 40. Therefore, it is possible to position the first sealing member 60 above the vehicle relative to the second sealing member 70 without complicating the structure of the battery case 22.

[0033] Furthermore, the second sealing member 70 prevents the liquid W from flowing to the supported portion 42E, which is part of the second outer circumference 39 of the battery case 22 and is joined to the rocker 12 and the cross member 14. As a result, corrosion of the supported portion 42E and the joints between the supported portion 42E and the rocker 12 and the cross member 14, caused by the liquid W adhering to the battery case 22, can be suppressed.

[0034] Furthermore, if, after a through hole 42X is formed in a part of the lower section 42, liquid W accumulates in the space enclosed by the front of the second sealing member 70, the front of the lower section 42, and the front of the hanging section 41 over a long period of time, a part of the lower section 31 may corrode, as shown in Figure 4, and a through hole 31X communicating with the through hole 42X may be formed in a part of the lower section 31. In this case, since the liquid W flows down to the lower part of the first outer circumference 28 through the through holes 42X and 31X, the risk of the liquid W adhering to the battery cell 54 is extremely small.

[0035] The vehicle understructures according to the embodiments have been described above, but these can be modified as appropriate without departing from the spirit of the present invention.

[0036] For example, the upper section 29, hanging section 30, and lower section 31 may be formed only on the front and rear of the first outer perimeter 28, while the upper section 40, hanging section 41, and lower section 42 may be formed only on the front and rear of the second outer perimeter 39. Alternatively, the upper section 29, hanging section 30, and lower section 31 may be formed only on the left and right sides of the first outer perimeter 28, while the upper section 40, hanging section 41, and lower section 42 may be formed only on the left and right sides of the second outer perimeter 39. [Explanation of Symbols]

[0037] 10 vehicles 12. Rocker (body frame component) 14. Cross member (body frame component) 22 Battery Case 24 Lower Cases 28. First outer perimeter (outer perimeter) 29 Upper section 31 Lower section 35 Upper Case 39. Second outer perimeter (outer perimeter) 40 Upper section 42 Lower section 42E Supported part (joined part) 54 battery cells 60 First sealing member 70 Second sealing member

Claims

1. A battery case comprising a lower case having a first outer periphery that constitutes the outer periphery, and an upper case having a second outer periphery that constitutes the outer periphery and faces the first outer periphery, with a battery cell housed inside, A vehicle body frame member that supports a part of the outer periphery, A first sealing member that contacts the opposing surfaces of the first outer periphery and the second outer periphery, A second seal member that contacts the outer periphery and the vehicle body frame member, and is located lower to the vehicle than the first seal member, A vehicle understructure equipped with the following features.

2. The first outer periphery and the second outer periphery each comprise an upper portion and a lower portion located further outward and below the upper portion. The first sealing member contacts the opposing surfaces of the upper portion of the first outer periphery and the second outer periphery. The vehicle understructure according to claim 1, wherein the second sealing member is in contact with the lower portion of the outer periphery and the vehicle body frame member.

3. A portion of the outer periphery is a joined portion that is joined to the vehicle body frame member. The vehicle understructure according to claim 1 or claim 2, wherein the second sealing member contacts the joined portion and the vehicle body frame member.

4. The vehicle understructure according to claim 1 or claim 2, wherein the upper surface of the upper case constitutes the floor panel of a vehicle equipped with the vehicle body frame member.

Images