Battery pack

Abstract

To provide a battery pack capable of suppressing buckling of frame members.SOLUTION: A battery pack includes: a plurality of battery cells stacked in a predetermined direction; an upper frame member arranged above the battery cells; and a lower frame member arranged below the battery cells. Further the upper frame member includes a reinforcing member which extends in a direction perpendicular to a stacking direction of the battery cells, and at least a portion of which overlaps with the lower frame member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a battery pack. [Background technology]

[0002] Patent document 1 discloses a structure that improves maintainability by providing an under-cover placed below the battery pack with a cover piece that is fastened to the battery pack but does not cover the battery fastening position from below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-142416 Summary of the Invention [Problem to be solved by the invention]

[0004] A frame member is disposed between each battery cell of the battery pack. In such a battery pack, in the case where a side impact load is applied from the outside to the portion where the battery cells are disposed on both sides of the frame member, the load applied through the frame member is borne equally by the battery cells on both sides.

[0005] On the other hand, in the case of battery cells located at the very edge of a battery pack, i.e., in a section where battery cells are located on only one side of a frame member, if an external side impact load is applied, the load applied through the frame member will be borne by only the battery cells on that side. As a result, when a side impact load is applied, the frame member may buckle (break in an L-shape) in the direction where the battery cells are not located, and an excessive load may be applied to the battery cells.

[0006] The present disclosure has been made in view of the above, and has an object to provide a battery pack that can suppress buckling of a skeletal member. [Means for solving the problem]

[0007] The battery pack according to the present disclosure comprises a plurality of battery cells stacked in a predetermined direction, an upper skeletal member arranged above the battery cells, a lower skeletal member arranged below the battery cells, and a reinforcing member that extends in a direction perpendicular to the stacking direction of the battery cells and at least a portion of which overlaps with the lower skeletal member. [Effects of the Invention]

[0008] According to the present disclosure, buckling of the upper skeletal member can be suppressed by reinforcing the portion where there is no lower skeletal member (in the direction in which the upper skeletal member buckles), which is a weak point in the event of a side impact load, with a reinforcing member. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view showing the configuration of a battery pack according to an embodiment. [Figure 2] FIG. 2 is an enlarged plan view of the X portion of the battery pack in FIG. [Figure 3] FIG. 3 is a cross-sectional view showing the battery pack of FIG. 1 cut at the line AA. [Figure 4] FIG. 4 is a cross-sectional view showing the conventional battery pack taken along the same line AA as in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing the battery pack of FIG. 1 cut at the line BB. [Figure 6] FIG. 6 is a plan view showing the configuration of a conventional battery pack. [Figure 7] FIG. 7 is a plan view showing the configuration of the battery pack according to the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing the battery pack of FIG. 6 cut at the line CC. [Figure 9] FIG. 9 is a cross-sectional view showing the battery pack of FIG. 6 cut at the position of line DD. [Figure 10]FIG. 10 is a cross-sectional view showing the battery pack of FIG. 7 cut at the position of line EE. DETAILED DESCRIPTION OF THE INVENTION

[0010] A battery pack according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially the same.

[0011] The battery pack according to the embodiment is used as a battery for a vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a battery electric vehicle (BEV).

[0012] Fig. 1 shows a battery pack according to an embodiment with an upper cover (lid member) removed. Fig. 2 shows an enlarged view of the X portion of the battery pack shown in Fig. 1. Fig. 3 shows the battery pack shown in Fig. 1 cut along line AA.

[0013] The battery pack 1 includes a lower case (housing member) 11, a plurality of battery cells 12, a plurality of upper frame members 13, a reinforcing member 14, a plurality of lower frame members 15, a shear panel 16, and a connecting member 18.

[0014] The lower case 11 is for housing each component of the battery pack 1. The battery cells 12 are liquid batteries such as lithium ion secondary batteries. The battery cells 12 are stacked in the longitudinal direction of the battery pack 1 to form a battery module.

[0015] The upper skeletal member 13 is a member that forms a skeleton within the lower case 11. As shown in FIG. 1, the upper skeletal member 13 is a rod-shaped member that extends in the width direction of the battery pack 1. The upper skeletal member 13 is disposed above the battery cells 12 in the height direction of the battery pack 1. Note that the "height direction of the battery pack 1" refers to the direction (thickness direction of the battery pack 1) that is perpendicular to the length direction and width direction of the battery pack 1 shown in FIG. 1.

[0016] 1 and 2, the upper frame member 13 is provided on the side surfaces of the plurality of battery cells 12 in the stacking direction of the battery cells 12 (the length direction of the battery pack 1). The upper frame member 13 also includes reinforcing members 14 as shown in FIG.

[0017] The reinforcing member 14 is intended to reinforce the upper frame member 13. As shown in FIG. 2, the reinforcing member 14 extends in a direction perpendicular to the stacking direction of the battery cells 12 (the length direction of the battery pack 1), i.e., in the width direction of the battery pack 1. The reinforcing member 14 is provided on the outside of the battery cell 12 arranged at the extreme end in the stacking direction of the battery cells 12. Note that the "battery cell 12 arranged at the extreme end" refers to the battery cell 12 arranged at the extreme rear side of the vehicle, as shown in FIG. 2. In other words, the "battery cell 12 arranged at the extreme end" refers to a battery cell 12 that has another battery cell 12 arranged on only one side (the left side in FIG. 2) and no other battery cell 12 arranged on the opposite side (the right side in FIG. 2).

[0018] 3, at least a portion of the reinforcing member 14 overlaps with the lower skeletal member 15. Note that "the reinforcing member 14 overlaps with the lower skeletal member 15" means that the reinforcing member 14 and the lower skeletal member 15 overlap (overlap) in the height direction of the battery pack 1.

[0019] Here, as shown in Fig. 4, the conventional battery pack 101 does not include a reinforcing member 14, but instead has a connecting member 18 provided at a position corresponding to the reinforcing member 14. The connecting member 18 does not overlap the lower skeletal member 15. Therefore, for example, when a side collision load is applied from the outside, the gap between the connecting member 18 and the lower skeletal member 15, as shown by part Z in Fig. 4, becomes a weak point (a breakage point), and there is a risk that the upper skeletal member 13 will buckle.

[0020] On the other hand, in the battery pack 1 according to the embodiment, as shown in part Y in Fig. 3, at least a part of the reinforcing member 14 is overlapped with the lower frame member 15, thereby eliminating the weak point (see part Z in Fig. 4) found in the conventional battery pack 101. This makes it possible to suppress buckling of the upper frame member 13 even when a side impact load is applied from the outside.

[0021] Similar to the upper skeletal member 13, the lower skeletal member 15 is a member that constitutes a skeleton within the lower case 11. Similar to the upper skeletal member 13, the lower skeletal member 15 is a rod-shaped member that extends in the width direction of the battery pack 1. The lower skeletal member 15 is also disposed below the battery cells 12 in the height direction of the battery pack 1.

[0022] 5, the lower frame member 15 is fastened to a shear panel 16 with fastening members 17. The shear panel 16 is used to protect the lower surfaces of the battery cells 12, and is disposed at the bottom of the lower case 11.

[0023] The connecting members 18 are used to support the upper frame members 13 and to connect the upper frame members 13 to each other. As shown in Fig. 1, the connecting members 18 are disposed at the ends of the upper frame members 13 between the battery cells 12. Furthermore, as shown in Fig. 2, instead of the connecting members 18, reinforcing members 14 are disposed on the outer side of the battery cell 12 that is disposed at the end in the stacking direction of the battery cells 12.

[0024] Here, Fig. 6 shows the configuration of a conventional battery pack 101. Fig. 7 shows the configuration of a battery pack 1 according to the embodiment. Figs. 8 and 9 show the battery pack 101 of Fig. 6 cut at the positions of lines CC and DD. Fig. 10 shows the battery pack 1 of Fig. 7 cut at the position of line EE. Note that the DD line in Fig. 6 and the EE line in Fig. 7 are at the same position.

[0025] In a conventional battery pack 101, as shown in Fig. 8, for example, the portion where the upper skeletal member 13 and the lower skeletal member 15 overlap has a high total plastic moment, so even if a side collision load is input, buckling of the upper skeletal member 13 is unlikely to occur. In contrast, as shown in Fig. 9, for example, the portion where the upper skeletal member 13 and the lower skeletal member 15 do not overlap has a low total plastic moment, so there is a risk that the upper skeletal member 13 will buckle (bend in a dogleg toward the rear of the vehicle) if a side collision load is input.

[0026] On the other hand, in the battery pack 1 according to the embodiment, as shown in Fig. 10, the portion where the upper skeletal member 13 and the lower skeletal member 15 do not overlap is reinforced by the reinforcing member 14. In this way, in the battery pack 1 according to the embodiment, the portion where the lower skeletal member 15 does not exist (the direction in which the upper skeletal member 13 buckles), which is a weak point in the event of a side collision load, is reinforced by the reinforcing member 14, so that the side collision load can be borne by the reinforcing member 14. This makes it possible to suppress buckling of the upper skeletal member 13.

[0027] Further advantages and modifications will readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0028] 1,101 battery packs 11 Lower case 12 battery cells 13 Upper frame member 14 Reinforcement member 15 Lower frame member 16 Share Panel 17 Fastening members 18 Connecting member

Claims

1. A plurality of battery cells stacked in a predetermined direction; an upper frame member disposed above the battery cell; a lower framework member disposed below the battery cell; the upper skeletal member includes a reinforcing member that extends in a direction perpendicular to the stacking direction of the battery cells and at least a portion of which overlaps with the lower skeletal member; Battery pack.

2. the upper frame member is provided on a side surface of the plurality of battery cells in the stacking direction, the reinforcing member is provided on the outer side of the battery cell arranged at the end in the stacking direction. The battery pack according to claim 1 .

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