Battery pack

Abstract

To provide a battery pack that has an excellent water detection capability, and has a small size.SOLUTION: A battery pack comprises: a plurality of battery stacks arranged in a first direction; a frame surrounding the plurality of battery stacks; and a cross member provided between the battery stacks. The frame has: first and second portions extending in a second direction vertical to the first direction; and third and fourth portions extending in the first direction. In each cross member, a first notch part penetrating in the first direction is formed at a position of a predetermined distance toward a second end surface brought into contact with the fourth portion from a first end surface brought into contact with the third portion. In the first portion, a space extending in the second direction is formed, and a second notch part communicating with the space is formed on the battery stack side. In a side surface view to the first portion side from the second portion side, a part of the second notch part is overlapped with each first notch part. The battery pack comprises a water detection sensor installed at a position overlapped with the second notch part in the side surface view in the space.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] Conventionally, various electric vehicles such as hybrid cars and electric cars are equipped with battery packs. For example, JP 2021-34156 A (Patent Document 1) discloses a high-voltage device as the battery pack. The high-voltage device includes a battery unit, a case having a peripheral wall portion with a cable insertion port opening to the side and accommodating the battery unit, and a water detection sensor disposed in a portion of the case below the cable insertion port and located near the peripheral wall portion, for detecting water that has entered the case ("Summary"). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-34156 A Summary of the Invention [Problem to be solved by the invention]

[0004] For the sake of functionality, the water detection sensor needs to be placed near the bottom surface of the high-voltage device (battery pack). Therefore, in Patent Document 1, the case of the battery unit (battery stack) is made large to ensure an installation area for the water detection sensor. Thus, when the water detection sensor is installed in the battery pack, the battery pack becomes large.

[0005] The present disclosure has been made in consideration of the above problems, and has an object to provide a small-sized battery pack that has excellent water detection capability. [Means for solving the problem]

[0006] According to an aspect of the present disclosure, a battery pack includes a substrate extending along a first direction and a second direction perpendicular to the first direction, a plurality of battery stacks arranged in the first direction on the substrate, a frame disposed on the substrate and surrounding the plurality of battery stacks in a top view of the battery pack, and one or more cross members each provided between the battery stacks on the substrate and each extending in the second direction within the frame. The frames have first and second portions facing each other and each extending in the second direction, and third and fourth portions connected to the first and second portions and each extending in the first direction. Each cross member has a first end face abutting the third portion and a second end face abutting the fourth portion. A first cutout penetrating the cross member in the first direction is formed on the substrate side and at a predetermined distance from the first end face toward the second end face. A space extending in a second direction is formed inside the first section. Second cutouts communicating with the space are formed on the substrate side and the battery stack side in the first section. At least a portion of the second cutouts overlaps with each of the first cutouts in a side view of the battery pack from the second section side to the first section side. The battery pack further includes a water detection sensor installed in the space at a position overlapping with the second cutouts in a side view.

[0007] According to this configuration, the first cutouts of each cross member ensure a flow path through which water can easily flow, so that water that has accumulated in the battery pack can be quickly detected. In other words, the battery pack has excellent water detection capabilities. Furthermore, since the second cutouts are provided in the first portion and the water detection sensor is installed in the space within the first portion, there is no need to provide installation space for the water detection sensor in an area within the frame (area on the substrate). This makes it possible to avoid increasing the size of the battery pack and to reduce its size. In this way, the battery pack has excellent water detection capabilities and can be made compact. Effect of the Invention

[0008] According to the present disclosure, the battery pack has excellent water detection capability and can be made compact. [Brief description of the drawings]

[0009] [Figure 1] FIG. [Diagram 2] 2 is a diagram showing a state in which a battery stack and an electric device are removed from the battery pack shown in FIG. 1. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] 11 is a perspective view for explaining the flow of water and the detection of water when water that has entered the battery pack accumulates on the base material. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same members are denoted by the same reference numerals. The names and functions of the members are also the same. Therefore, detailed description thereof will not be repeated.

[0011] 1, the battery pack 1 includes a plurality of battery stacks 71-75, a plurality of cross members 31-, an electric device 80, and a frame 20. As shown in FIG.

[0012] The battery pack 1 is mounted on an electrically powered vehicle such as a hybrid vehicle capable of running using at least one of the power of a motor and an engine, or an electric vehicle that runs using driving force obtained from electric energy.

[0013] 1, the D1 direction is the front-rear direction of the electric vehicle, and the D2 direction is the left-right direction of the electric vehicle. For ease of explanation, any one of the battery stacks 71-75 will be referred to as "battery stack 70" below. Any one of the cross members 31-34 will be referred to as "cross member 30" below.

[0014] The multiple battery stacks 71 to 75 are lined up in a row in this order in the direction D1. In this example, among the multiple battery stacks 71 to 75, the battery stack 71 is located closest to the front of the electric vehicle. The electric device 80 is installed above the battery stack 75.

[0015] In a top view of the battery pack, the frame 20 surrounds the plurality of battery stacks 71 to 75. Inside the frame 20, the plurality of battery stacks 71 to 75 are arranged.

[0016] The cross member 31 is provided between the battery stack 71 and the battery stack 72. Similarly, the cross members 32, 33, and 34 are provided between the battery stack 72 and the battery stack 73, between the battery stack 73 and the battery stack 74, and between the battery stack 74 and the battery stack 75, respectively. In this manner, each cross member 30 is provided between two adjacent battery stacks 70.

[0017] The battery pack 1 is attached to support members 90R, 90L on the vehicle body side. More specifically, the frame 20 is fixed to the support members 90R, 90L with bolts. The support member 90R is located to the right of the support member 90L on the electric vehicle.

[0018] Fig. 2 is a diagram showing a state in which the battery stacks 71-75 and the electric device 80 have been removed from the battery pack 1 shown in Fig. 1. As shown in Fig. 2, the battery pack 1 includes a base material 10 and a water detection sensor 40 in addition to the frame 20 and each cross member 30.

[0019] The substrate 10 extends along a direction D1 and a direction D2 perpendicular to the direction D1. The frame 20 and each cross member 30 are installed on the substrate 10. The frame 20 and each cross member 30 are fixed to the substrate 10 with bolts. Similarly, each battery stack 70 shown in FIG. 1 is also installed on the substrate 10.

[0020] The substrate 10 includes a bottom portion 11 and a plurality of mounting portions 12. Each mounting portion 12 has a first region 121, a second region 122, and a third region 123. The first region 121, the second region 122, and the third region 123 are rectangular and extend in the D2 direction. The first region 121, the second region 122, and the third region 123 are arranged at intervals in the D1 direction. Thus, there is a gap between the first region 121 and the second region 122, and between the second region 122 and the third region 123.

[0021] The frame 20 and the cross members 30 are installed on the bottom 11. The bottom 11 also functions as a groove. One mounting portion 12 is located between the cross members 30. One battery stack 70 is placed on one mounting portion 12.

[0022] The frame 20 has a front frame portion 21, a rear frame portion 22, a right frame portion 23, and a left frame portion 24. The front frame portion 21 and the rear frame portion 22 face each other and each extend in the D2 direction. The right frame portion 23 and the left frame portion 24 are connected to the front frame portion 21 and the rear frame portion 22, respectively, and each extend in the D1 direction. In more detail, one end of the right frame portion 23 and the left frame portion 24 are connected to the front frame portion 21, and the other end is connected to the rear frame portion 22.

[0023] The frame 20 has a substantially frame-like shape when viewed from above the battery pack 1. The front frame portion 21 has an outer flange portion 211 and an inner flange portion 212. Similarly, the rear frame portion 22, the right frame portion 23, and the left frame portion 24 have outer flange portions 221, 231, and 241 and inner flange portions 222, 232, and 242, respectively. The outer flange portion 231 is fixed to the support member 90R shown in FIG. 1. The outer flange portion 241 is fixed to the support member 90L shown in FIG. 1.

[0024] The outer flange portions 211, 221, 231, and 241 and the inner flange portions 212, 222, 232, and 242 are rectangular protruding portions.

[0025] A space is formed inside the frame 20. A space extending in the D2 direction is formed inside the front frame portion 21 and the rear frame portion 22. A space extending in the D1 direction is formed inside the right frame portion 23 and the left frame portion 24. In this example, a closed space is formed by attaching the frame 20 to the base material 10 (more specifically, the bottom portion 11). A water detection sensor 40 is installed in the space inside the front frame portion 21.

[0026] The water detection sensor 40 is a sensor that detects water. The water detection sensor 40 detects water using long-wavelength light that is absorbed by water molecules. The water detection sensor 40 is communicatively connected to a control device (not shown). When the water detection sensor 40 detects water, it sends a predetermined signal to the control device. When the control device receives the signal, it displays a warning on a monitor of the electric vehicle, for example.

[0027] Each cross member 30 has flange portions 301, 302 in the D1 direction. The flange portion 301 is located forward of the flange portion 302. Each cross member 30 extends in the D2 direction within the frame 20. Each cross member 30 is fixed to the base material 10 with each end portion (FIG. 4) in the D2 direction abutting against the right frame portion 23 and the left frame portion 24. Each cross member 30 is fitted into the inside of the frame 20 in a fence shape.

[0028] In this example, the inner area of ​​the frame 20 is divided into five sections by the four cross members 31 to 34. In the following, the sections will be referred to as the "first section," the "second section," the "third section," the "fourth section," and the "fifth section" from the front frame portion 21 side toward the rear frame portion 22 side. For example, the first section is the area surrounded by the front frame portion 21, the right frame portion 23, the left frame portion 24, and the cross member 31 (the area on the base material 10).

[0029] At least the bottom portion 11 is present between the mounting portion 12 of the substrate 10 and the right frame portion 23 and the left frame portion 24. There is a gap between the mounting portion 12 and the right frame portion 23 and the left frame portion 24 in the D2 direction.

[0030] Fig. 3 is a side view of the front frame portion 21. More specifically, Fig. 3 is a view of the front frame portion 21 viewed from the rear frame portion 22 side. As shown in Fig. 3, the front frame portion 21 has an inner flange portion 212, side portions 213, 214, an upper portion 215, a bottom portion 216, and end faces 208, 209. In this example, the front frame portion 21 is formed by bending a single metal plate. However, the front frame portion 21 is not limited to this, and may be formed of a rectangular pipe.

[0031] The bottom portion 216 is a portion that comes into contact with the substrate 10. The top portion 215 is a portion opposite the bottom portion 216. The side portion 213 is a portion that continues to the inner flange portion 212. The side portion 214 is a portion that continues to the outer flange portion 211 (FIG. 2).

[0032] The side portion 213 has an opposing surface 213a facing the side portion 214. The side portion 214 has an opposing surface 214a facing the side portion 213. The upper portion 215 has an opposing surface 215a facing the substrate 10. The opposing surfaces 213a and 214a face each other.

[0033] A space Q extending in the D2 direction is formed inside the front frame portion 21. In detail, in this example, the space Q extending in the D2 direction is formed inside the front frame portion 21 by the opposing surfaces 213a, 214a, and 215a.

[0034] The end surface 208 is an abutment surface that abuts against the right frame portion 23. The end surface 209 is an abutment surface that abuts against the left frame portion 24. For this reason, the end surfaces 208, 209 cannot be seen from the outside unless the frame 20 is disassembled.

[0035] A cutout 290 that communicates with the space Q is formed in the front frame portion 21 on the substrate 10 side and on the battery stack 70 side. That is, the cutout 290 is formed in the side portion 213 on the bottom portion 216 side, not on the top portion 215 side. In this embodiment, the term "cutout" is a concept that also includes a through hole (communication hole).

[0036] In this example, the notch 290 has a substantially rectangular shape. However, the shape of the notch 290 is not particularly limited. The notch 290 is formed at a position between the distances L1 and L2 from the end face 208 toward the end face 209. It is preferable that the position between the distances L1 and L2 does not overlap with the placement portion 12 in a side view of the battery pack 1 from the rear frame portion 22 side to the front frame portion 21 side, from the viewpoint of not impeding the movement of water.

[0037] As described above, the water detection sensor 40 is disposed in the space Q. More specifically, the water detection sensor 40 is disposed at a position overlapping the notch 290 when viewed from the side of the battery pack 1 from the rear frame portion 22 side to the front frame portion 21 side. That is, the water detection sensor 40 is disposed at a position overlapping the notch 290 when viewed from the side of the battery pack 1 from the rear frame portion 22 side to the front frame portion 21 side. More specifically, a detection surface (not shown) of the water detection sensor 40 faces the rear frame portion 22.

[0038] The rear frame portion 22, the right frame portion 23, and the left frame portion 24 have the same configuration as the front frame portion 21, except that the cutout portion 290 is not formed. However, in this example, the right frame portion 23 and the left frame portion 24 are longer in the extension direction than the front frame portion 21 and the rear frame portion 22.

[0039] Fig. 4 is a side view of the cross member 31. More specifically, Fig. 4 is a view of the cross member 31 viewed from the rear frame portion 22 side. As shown in Fig. 4, the cross member 31 has a flange portion 302, side portions 303, 304, an upper portion 305, a bottom portion 306, and end faces 308, 309. The end face 308 abuts against the right frame portion 23 as shown in Fig. 2. The end face 309 abuts against the left frame portion 24.

[0040] The cross member 31 is hollow, similar to the front frame portion 21. In this example, the cross member 31 is formed by bending a single metal plate, similar to the front frame portion 21. However, the cross member 31 is not limited to this, and may be formed of a rectangular pipe.

[0041] The cross member 31 does not have to be hollow as described above. From the viewpoint of preventing water from accumulating inside the cross member 31, it is preferable that the cross member 31 is not hollow. On the other hand, from the viewpoint of reducing the weight of the cross member 31, it is preferable that the cross member 31 is hollow as described above.

[0042] The cross member 31 has a cutout 390 formed on the base material 10 side, penetrating in the D1 direction, at a position (a position at a predetermined distance) between the distance L1 and L2 from the end face 308 toward the end face 309. Specifically, the cutout 390 is formed on the side portions 303 and 304, not on the top 305 side but on the bottom 306 side. In this example, the cutout 390 is formed on each of the side portions 303 and 304.

[0043] In a side view of the battery pack 1 from the rear frame portion 22 side to the front frame portion 21 side, the notch 290 of the front frame portion 21 and the notch 390 of the cross member 31 overlap with each other. In this example, in the side view, the notch 290 and the notch 390 completely overlap with each other, but this is not limited thereto. It is sufficient that at least a portion of the notch 290 overlaps with the notch 390 in the side view.

[0044] The other cross members 32, 33, and 34 have the same configuration as the cross member 31, and therefore the configurations of the cross members 32, 33, and 34 will not be repeated here.

[0045] Fig. 5 is a perspective view for explaining the flow (movement) of water and the detection of water when water that has entered the battery pack 1 accumulates on the substrate 10. For the sake of convenience, the battery stack 70 placed on the mounting portion 12 is not shown in Fig. 5.

[0046] As shown in Fig. 5, the water W accumulated on the substrate 10 moves on the substrate 10 due to vibration of the electric vehicle. Typically, the water W flows through the bottom 11 (i.e., the groove portion) which is lower than the mounting portion 12. For example, when the electric vehicle decelerates, an inertial force from the rear frame portion 22 side to the front frame portion 21 side is applied to the water W. When the electric vehicle tilts and the front frame portion 21 side is lower than the rear frame portion 22 side, a force (a component force of gravity) that tries to move the water W toward the front frame portion 21 side is applied to the water W.

[0047] In such a case, for example, the water (not shown) in the second section flows into the first section closest to the front frame section 21 through the cutout 390 of the cross member 31. Similarly, the water (not shown) in the third to fifth sections also finally flows into the first section through the cutouts 390 in sequence. As described above, the cutouts 390 are formed at positions L1 to L2 from the end surface 308 as shown in FIG. 4. Therefore, the water passes through the cutouts 390 in sequence and flows into the first section without being impeded by the cross member 30. More specifically, the water W reaches the front frame section 21 along the extension direction (D1 direction) of the inner flange section 232 (FIG. 2) of the light frame section 23.

[0048] Thereafter, the water W in the first section flows into the space Q (FIG. 3) inside the front frame portion 21 through the cutout portion 290 of the front frame portion 21. As a result, the water W is detected by the water detection sensor 40 installed in the space Q.

[0049] More specifically, each notch 390 is formed at a position L1 to L2 from the end face 308 as shown in Fig. 4. The notch 290 is formed at a position L1 to L2 from the end face 208 as shown in Fig. 3. That is, each notch 390 and the notch 290 are formed at a location the same distance from the light frame portion 23. Therefore, water that passes through the cross member 31 quickly flows into the space Q without being impeded by the side portion 213 of the front frame portion 21.

[0050] In such a battery pack 1, the cutouts 390 of each cross member 30 provide a flow path through which water can easily flow, so that water accumulated in the battery pack 1 can be quickly detected. In other words, the battery pack has excellent water detection capabilities. Therefore, the driver of the electric vehicle can know at an early stage that water has accumulated in the battery pack 1.

[0051] Furthermore, since the front frame portion 21 is provided with the notch 290 and the water detection sensor 40 is installed in the space Q within the front frame portion 21, there is no need to provide an installation space for the water detection sensor 40 in an area within the frame 20 (an area on the base material 10). This makes it possible to avoid an increase in size of the battery pack 1 and to reduce its size.

[0052] As described above, the battery pack 1 has excellent water detection capability and can be made compact.

[0053] In the above description, the notches 290, 390 are provided on the right frame portion 23 side, but the present invention is not limited to this. The notches 290, 390 may be provided on the left frame portion 24 side.

[0054] Although the cutout 290 is provided in the front frame portion 21 and the water detection sensor 40 is provided in the space Q within the front frame portion 21, the present invention is not limited to this. The cutout 290 may be provided in the rear frame portion 22 and the water detection sensor 40 may be provided in the space within the rear frame portion 22.

[0055] In the case where the battery stack in the electric vehicle is arranged in the D2 direction (left-right direction) instead of the D1 direction (see FIG. 1) as described above, the battery pack 1 can be mounted on the electric vehicle in a state rotated 90 degrees around the vertical axis in a horizontal plane. In this case, typically, water on the substrate 10 moves when passing through a curve, and the water can be detected by the water detection sensor 40.

[0056] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the scope of the claims, and it is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. [Explanation of symbols]

[0057] 1 battery pack, 10 substrate, 11, 216, 306 bottom, 12 placement portion, 20 frame, 21 front frame portion, 22 rear frame portion, 23 right frame portion, 24 left frame portion, 31, 32, 33, 34 cross member, 40 water detection sensor, 71, 72, 73, 74, 75 battery stack, 80 electrical equipment, 90L, 90R support member, 121 first region, 122 second region, 123 third region, 211, 221, 231, 241 outer flange portion, 212, 222, 232, 242 inner flange portion, 213, 214, 303, 304 side portion, 213a, 214a, 215a opposing surface, 215, 305 upper portion, 290, 390 Notch, 301, 302 Flange, 208, 209, 308, 309 End, Q Space, W Water.

Claims

[Claim 1] A battery pack comprising: A substrate extending along a first direction and a second direction perpendicular to the first direction; A plurality of battery stacks arranged in the first direction on the substrate; a frame disposed on the base material and surrounding the plurality of battery stacks in a top view of the battery pack; one or more cross members each provided between the battery stacks on the base material and each extending in the second direction within a perimeter of the frame; the frame has first and second portions opposed to each other and each extending in the second direction, and third and fourth portions connected to the first and second portions and each extending in the first direction; Each of the cross members has a first end surface abutting against the third portion and a second end surface abutting against the fourth portion, Each of the cross members has a first cutout formed on the base material side and at a predetermined distance from the first end face toward the second end face, the first cutout penetrating in the first direction, A space extending in the second direction is formed inside the first portion, a second cutout portion communicating with the space is formed in the first portion on the substrate side and on the battery stack side, When viewed from a side of the battery pack from the second portion to the first portion, at least a portion of the second cutout portion overlaps with each of the first cutout portions; The battery pack further includes a water detection sensor disposed within the space at a position overlapping the second cutout portion in the side view.

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