Battery pack

Abstract

The utility model relates to a battery pack. The battery pack includes an upper cover and a lower case. The upper cover is disposed so as to face the floor of the vehicle. The lower housing is combined with the upper cover. In the width direction of the vehicle, the opening edge portion of the lower housing is combined with the left end portion and the right end portion of the upper cover to form a left flange and a right flange respectively. In the width direction of the vehicle, the upper surfaces of the left flange and the right flange are located below the upper surface of the upper cover facing the floor. The upper surface of the upper cover opposite to the floor and the upper surfaces of the left flange and the right flange form steps.

Description

Technical Field

[0001] The present disclosure relates to a battery pack that houses a battery stack mounted on a vehicle. Background Art

[0002] Japanese Patent No. 6451685 discloses an installation structure of a battery pack installed on the underbody of a vehicle. In this conventional structure, the underbody includes a floor that is installed on a vehicle's skeletal member. The battery pack includes an upper cover disposed opposite to the floor, and a lower housing combined with the upper cover. A battery stack is housed in a space formed between the upper cover and the lower housing. In addition, frames are respectively provided on the sides of the battery pack at the front and rear of the vehicle. The battery pack is installed on the skeletal member via these frames. That is, in the conventional structure, the battery pack is installed on the underbody at the positions of the skeletal members on the front and rear sides of the vehicle. Summary of the Utility Model

[0003] Consideration is given to installing the battery pack on the left and right skeletal members of the vehicle. In this case, it is important to maintain the structure of the battery pack when an external force is input from the left or right direction. However, since the upper cover of the battery pack in the conventional structure is a simple plate-like member, there is a problem that the mating surface of the upper cover that mates with the lower housing is likely to open.

[0004] One of the objects of the present disclosure is to provide a battery pack with high resistance to external forces input from the left or right direction of the vehicle when the battery pack is installed on the left and right skeletal members of the vehicle.

[0005] The present disclosure is a battery pack that houses a battery stack mounted on a vehicle, and has the following features. The battery pack includes an upper cover and a lower housing. The upper cover is disposed opposite to the floor of the vehicle. The lower housing is combined with the upper cover.

[0006] In the width direction of the vehicle, an opening edge portion of the lower housing is combined with a left end portion and a right end portion of the upper cover to respectively form a left flange and a right flange. The left flange is installed on the left skeletal member of the vehicle provided on the left side of the floor. The right flange is installed on the right skeletal member of the vehicle provided on the right side of the floor.

[0007] In the width direction, upper surfaces of the left flange and the right flange are located at positions lower than an upper surface of the upper cover opposite to the floor. A step (height difference) is formed between the upper surface of the upper cover opposite to the floor and the upper surfaces of the left flange and the right flange.

[0008] According to the battery pack of the present disclosure, the upper surface of the upper cover forms a step with the upper surfaces of the left flange and the right flange. Therefore, the step can resist the external force input from the left or right direction of the vehicle to inhibit the opening of the mating surface between the upper cover and the lower housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Hereinafter, the features, advantages, and technical and industrial significance of the exemplary embodiments of the present utility model will be described with reference to the drawings. The same reference numerals denote the same elements in the drawings, and wherein:

[0010] Figure 1 is a diagram showing a configuration example of the battery pack according to the embodiment of the present disclosure.

[0011] Figure 2 is a diagram illustrating a configuration example of the battery pack according to the embodiment.

[0012] Figure 3 is showing Figure 2 the characteristic part of the battery pack shown.

[0013] Figure 4 is a diagram illustrating the effect of the battery pack according to the embodiment.

[0014] Figure 5 is a diagram illustrating the effect of the battery pack according to the embodiment.

[0015] Figure 6 is a diagram illustrating the effect of the battery pack according to the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. However, the structures and the like described in the following embodiments are not necessarily essential for the present utility model, except in cases where they are specifically indicated or clearly determined to be such structures in principle.

[0017] 1. Battery Pack

[0018] Figure 1 is a diagram showing a configuration example of the battery pack 1 according to the embodiment of the present disclosure. Figure 2 is a diagram illustrating a configuration example of the battery pack 1. In addition, Figure 1 the X-axis shown corresponds to the front-rear direction (length direction) of the vehicle VH, Figure 1 and Figure 2 the Y-axis shown corresponds to the left-right direction (width direction) of the vehicle VH, Figure 2 and the Z-axis shown corresponds to the up-down direction (height direction) of the vehicle VH. More specifically, the positive direction of the X-axis corresponds to the front direction, the positive direction of the Y-axis corresponds to the right direction, and the positive direction of the Z-axis corresponds to the up direction.

[0019] As shown in Figure 1 and Figure 2 , the battery pack 1 is installed at the bottom 2 of the vehicle body of the vehicle VH. The bottom 2 of the vehicle body includes a right frame member (right side frame) 21, a left frame member (left side frame) 22, and a floor 23. The floor 23 is spanned between the right frame member 21 and the left frame member 22. The installation positions of the battery pack 1 and the bottom 2 of the vehicle body are the lower surfaces of the right frame member 21 and the left frame member 22 (that is, the positions outside the passenger compartment). For example, the battery pack 1 is installed on the bottom 2 of the vehicle body by fastening connection members that connect the lower surface of the battery pack 1 to the upper surface of the bottom 2 of the vehicle body.

[0020] As shown in Figure 2 , the battery pack 1 includes an upper cover 11 and a lower housing 12. The upper cover 11 is composed of a central portion 11a, a right end portion 11b, and a left end portion 11c. The central portion 11a faces the floor 23. The right end portion 11b faces the right frame member 21. The left end portion 11c faces the left frame member 22. The upper surface of the central portion 11a is located above the upper surfaces of the right end portion 11b and the left end portion 11c. The upper surface of the central portion 11a and the upper surfaces of the right end portion 11b and the left end portion 11c form a step.

[0021] The lower housing 12 is composed of a housing portion 12a and an opening edge portion 12b that extends in the left - right direction of the vehicle VH at the opening position of the housing portion 12a. The lower housing 12 is combined with the upper cover 11. The battery stack 3 is housed in the space 13 surrounded by the lower surface of the central portion 11a, the upper surface, and the side surfaces of the housing portion 12a. The battery stack 3 is formed by stacking a plurality of single cells. In Figure 2 the example shown, the stacking direction of the plurality of single cells is the width direction of the vehicle VH. The battery stack 3 is a secondary battery capable of charging and discharging, and as such a secondary battery, a lithium - ion secondary battery is exemplified.

[0022] The combined position of the upper cover 11 and the lower housing 12 is the position where the right end portion 11b and the left end portion 11c respectively face the opening edge portion 12b. The right end portion 11b combined with the opening edge portion 12b forms a right flange 6, and the left end portion 11c combined with the opening edge portion 12b forms a left flange 7 (refer to Figure 3 ). At the position of the right flange 6, a sealing member (for example, sealing rubber) 4 that seals the space formed between them is provided between the lower surface of the right end portion 11b and the surface of the opening edge portion 12b. A sealing member 5 having the same function as the sealing member 4 is provided at the position of the left flange 7.

[0023] Hereinafter, for the sake of convenience of explanation, reference is also made to the Figure 2 simplified Figure 3 battery pack 1 shown in Figure 3It represents Figure 2 a diagram of the characteristic part of the battery pack 1 shown. Figure 3 The positions of the right flange 6 and the left flange 7 are shown. From this diagram, it can be seen that the right flange 6 and the left flange 7 are located above the battery stack 3, and when observing the battery pack 1 in the direction parallel to the Y-axis, these flanges do not appear to overlap with the battery stack 3. In Figure 3 the upper surface 31 of the battery stack 3 is also shown. This upper surface 31 is located below the surface of the opening edge portion 12b that contacts the sealing members 4 and 5.

[0024] 2. Effects

[0025] Figures 4 - 6 It is a diagram for explaining the effects of the battery pack 1 according to the embodiment. In Figure 4 and Figure 5 the battery packs 8 and 9, which are similarly simplified as the battery pack 1 shown in Figure 3 , are respectively depicted. The battery packs 8 and 9 are comparative examples of the battery pack 1 according to the embodiment. The difference in the configuration of each of the battery packs 8 and 9 from the configuration of the battery pack 1 shown in Figure 3 lies in the positions of the right flange and the left flange. The right flange and the left flange in the battery pack 8 are located at positions higher than the right flange and the left flange in the battery pack 1. On the other hand, the right flange and the left flange in the battery pack 9 are located at positions lower than the right flange and the left flange in the battery pack 1.

[0026] Specifically, in the battery pack 8, the upper cover 81 extends linearly in the direction parallel to the Y-axis, and there is no step at the end of the upper cover 81. Instead, the opening edge portion of the lower housing 82 moves in the positive Z-axis direction. On the other hand, in the battery pack 9, the right end portion of the upper cover 91 and the opening edge portion of the lower housing 92 that respectively contact the sealing member 4 are located below the upper surface 31. The left end portion of the upper cover 91 and the opening edge portion of the lower housing 92 that respectively contact the sealing member 5 are also located below the upper surface 31.

[0027] In Figure 4 a diagram of the transmission example of the external force F input to the battery pack 8 in the case of a side collision is shown. In the positive direction of the Y-axis, the right flange of the battery pack 8 is located on the outermost side. Therefore, in the case of a side collision, the external force F first acts on the right flange. In this way, the mating surface between the upper cover 81 that constitutes the right flange and the opening edge portion of the lower housing 82 may be easily opened, and the sealing structure of the right flange cannot be maintained.

[0028] In Figure 5 a diagram of the transmission example of the external force F in the case of a side collision is also shown. In this example, since the right flange moves in the negative direction of the Y-axis, the upper cover 91 and the lower housing 92 connected to the right flange may bite into the battery stack 3. In Figure 5Also shown is (ii) an example of the movement of the gas G (e.g., combustible gas) ejected from the battery cells constituting the battery stack 3. In this example, since the gas G generated at a position near the right flange is directly ejected onto the sealing member 4, there is a possibility of impairing the function of the sealing member 4 and the gas G leaking to the outside of the battery pack 1. In Figure 5 Also shown is (iii) an example of the movement of the heat H generated by the battery stack 3. In this example, the heat H tends to accumulate between the vehicle body bottom 2 and the right and left flanges, and it may be necessary to cool the battery stack 3.

[0029] Regarding this point, according to the battery pack 1 according to the embodiment, it is possible to reduce Figure 4 and Figure 5 the adverse conditions described in Figure 6 As shown, (i) in the case of a side collision, the step formed on the upper cover 11 resists the external force F, so it is possible to suppress Figure 4 the opening of the mating surface described in Figure 5 In addition, it is also possible to avoid Figure 5 the biting described in Figure 5 Furthermore, (ii) even if the gas G is ejected at a position near the right flange, it is possible to suppress the gas G from directly hitting the sealing member 4. Moreover, (iii) the heat H generated by the battery stack 3 easily dissipates into the atmosphere, so it is also possible to suppress Figure 5 the heat accumulation described in

Claims

1. A battery pack that houses a battery stack mounted on a vehicle, characterized in that: have: an upper cover disposed opposite to a floor of the vehicle; and The lower shell is combined with the upper cover. In the width direction of the vehicle, the opening edge of the lower shell is combined with the left end and the right end of the upper cover to form a left flange and a right flange respectively. The left flange is mounted on a left frame member of the vehicle, the left frame member is disposed on the left side of the floor, and the right flange is mounted on a right frame member of the vehicle, the right frame member is disposed on the right side of the floor. The upper surfaces of the left flange and the right flange in the width direction are located below the upper surface of the upper cover facing the floor. An upper surface of the upper cover facing the floor forms a step with upper surfaces of the left flange and the right flange.

2. The battery pack according to claim 1, characterized in that: The left flange and the right flange in the width direction are located above the battery stack.

3. The battery pack according to claim 1 or 2, characterized in that: The upper surface of the battery stack is located below the surface of the opening edge portion that faces the lower surfaces of the left end portion and the right end portion at each position of the left flange and the right flange.

4. The battery pack according to claim 3, characterized in that: A sealing member is provided between the lower surface of the left end portion and the surface of the opening edge portion opposite to the lower surface of the left end portion to seal a gap formed between these surfaces. A sealing member is provided between the lower surface of the right end portion and the surface of the opening edge portion that faces the lower surface of the right end portion and seals a gap formed between these surfaces.

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