Battery pack

Abstract

To obtain a battery pack that can suppress displacement upward of the vehicle during a side collision. [Solution] The battery pack 10 comprises a battery module 12, a lower case 14 to which the battery module 12 is fixed, an upper frame 16 positioned above the lower case 14 on the vehicle side, and support members 18 positioned on both sides in the vehicle width direction relative to the battery module 12. The support members 18 are fixed to the lower case 14 and the upper frame 16 in a state where they are stretched vertically between the lower case 14 and the upper frame 16, and support the upper frame 16 from below. A first deformation starting point portion 18A is provided on the side of the support member 18 that is fixed to the lower case 14, which serves as the deformation starting point when the support member 18 tilts to one side in the vehicle width direction.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 below discloses a battery pack installed in a vehicle, a dwelling, or the like. The battery pack described in this document includes a plurality of battery modules. A frame having an outer peripheral frame portion surrounding the outer periphery of the battery module is attached to the battery module. The frame includes a fixing portion for the battery module, a fixing portion for receiving another frame, and a fixing portion for another member. And the frame enables stacking of a plurality of battery modules. Furthermore, the outer peripheral frame portion of the frame has high rigidity against deformation of the battery module. Thereby, it is possible to realize a structure in which a plurality of battery modules are stacked while suppressing deformation of the battery module.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a battery pack is mounted on a vehicle, depending on the positional relationship between the battery pack and the devices around the battery pack, it may be desirable to reduce the amount of displacement of the battery pack upward of the vehicle during a side collision of the vehicle.

[0005] In consideration of the above facts, an object of the present invention is to obtain a battery pack capable of suppressing displacement upward of the vehicle during a side collision of the vehicle.

Means for Solving the Problems

[0006] The battery pack of the first embodiment comprises a battery module comprising a plurality of battery cells, a lower floor member to which the battery module is fixed, an upper floor member positioned above the lower floor member, support members positioned on both sides in the vehicle width direction relative to the battery module and fixed to the lower floor member and the upper floor member in a manner that spans the vehicle vertically between the lower floor member and the upper floor member, and supporting the upper floor member from below, and a first deformation starting point portion provided on the side of the support member that is fixed to the lower floor member, which serves as the deformation starting point when the support member tilts to one side in the vehicle width direction.

[0007] In the first embodiment of the battery pack, the battery module is fixed to the lower floor member. An upper floor member is provided on the vehicle-upper side of the battery module fixed to the lower floor member. Support members are provided on both sides of the vehicle width direction of the battery module fixed to the lower floor member, spanning between the lower floor member and the upper floor member. When a load is applied to the upper floor member in one direction in the vehicle width direction due to a side collision of the vehicle, the upper floor member is displaced to that side in the vehicle width direction, and the first deformation starting point provided on the fixing portion of the support member to the lower floor member deforms, causing the support member to tilt to that side in the vehicle width direction. As a result, peeling or fracture of the fixing portion of the support member to the lower floor member is suppressed, and the displacement of the upper floor member to the upper side of the vehicle can be suppressed. In other words, the displacement of the battery pack to the upper side of the vehicle can be suppressed.

[0008] The second embodiment of the battery pack is provided in the first embodiment of the battery pack, wherein a load-receiving portion is provided on the outer side in the vehicle width direction relative to the upper floor member, to which the upper floor member, displaced to one side in the vehicle width direction, makes contact, and a second deformation initiation point is provided in the intermediate part in the vehicle vertical direction between the first deformation initiation point and the upper floor member of the support member, which serves as the deformation initiation point when the upper floor member falls to the other side in the vehicle width direction after contacting the load-receiving portion.

[0009] In the second embodiment of the battery pack, when a load is applied to one side in the vehicle width direction, causing the upper floor member to be displaced to that side in the vehicle width direction, the upper floor member comes into contact with the load receiving portion, and the second deformation starting point of the support member deforms. By deforming the support member in this way so that the second deformation starting point becomes a deformation starting point in addition to the first deformation starting point, the displacement of the upper floor member upwards on the vehicle can be further suppressed. In other words, the displacement of the battery pack upwards on the vehicle can be further suppressed.

[0010] The third embodiment of the battery pack is such that, in the battery pack of the second embodiment, a plurality of the battery modules are stacked in the vehicle's vertical direction and connected in the vehicle's vertical direction, and the position of the second deformation starting point in the vehicle's vertical direction is set to the same position as the position of the connection portion between one battery module and another battery module in the vehicle's vertical direction.

[0011] In the third embodiment of the battery pack, the position of the second deformation starting point of the support member in the vehicle's vertical direction is set to the same position as the position of the connection portion between one battery module and another battery module in the vehicle's vertical direction. In this configuration, when the second deformation starting point deforms, it is possible to suppress the second deformation starting point, which has deformed toward the battery module, from coming into contact with the one battery module and the other battery module.

[0012] The fourth embodiment of the battery pack is a battery pack of the second or third embodiment, wherein the support member is provided with a third deformation initiation point on the side of the fixing portion with the upper floor member, which serves as the deformation initiation point after the upper floor member comes into contact with the load receiving portion.

[0013] In the fourth embodiment of the battery pack, when a load is applied to one side in the vehicle width direction, causing the upper floor member to be displaced to that side in the vehicle width direction, the upper floor member comes into contact with the load receiving portion, and the third deformation starting point of the support member deforms. By deforming the support member in this way so that the third deformation starting point becomes a deformation starting point in addition to the first and second deformation starting points, the displacement of the upper floor member upwards on the vehicle can be further suppressed. In other words, the displacement of the battery pack upwards on the vehicle can be further suppressed.

[0014] The fifth embodiment of the battery pack is a battery pack of any one embodiment of the first to fourth embodiments, wherein the plurality of battery cells are all solid-state batteries and are arranged in a line in the front-rear direction of the vehicle, and end plates are fixed to the front end and rear end of the battery module, respectively, and the end plates are fixed to the lower floor member and the upper floor member, respectively.

[0015] In the fifth embodiment of the battery pack, end plates are fixed to the front and rear ends of the battery module, respectively. The end plates are also fixed to the lower and upper floor members, respectively. In this configuration, the upper floor member is fixed to the end plates of the battery module and the lower floor member, which further suppresses upward displacement of the upper floor member. In particular, since all-solid-state batteries have a highly rigid structure due to the strong restraining pressure applied, the displacement of the upper floor member upward of the vehicle can be further suppressed. In other words, the displacement of the battery pack upward of the vehicle can be further suppressed. [Effects of the Invention]

[0016] The battery pack according to the present invention has the excellent effect of being able to suppress displacement toward the upward side of the vehicle during a side collision with the vehicle. [Brief explanation of the drawing]

[0017] [Figure 1] This is a perspective view showing the battery pack with the upper cover removed. [Figure 2] This is a cross-sectional view showing the battery pack cut along the width and vertical directions of the vehicle. [Figure 3] This is a cross-sectional view corresponding to Figure 2, schematically illustrating the situation when a collision load is applied due to a side collision. [Figure 4] This is a cross-sectional view corresponding to Figure 3, showing the deformed state of the first deformation initiation point, the second deformation initiation point, and the third deformation initiation point. [Modes for carrying out the invention]

[0018] Hereinafter, a battery pack 10 according to an embodiment of the present invention will be described with reference to the drawings. Arrows FR shown as appropriate in each figure indicate the front of the vehicle, arrow UP indicates the upper side of the vehicle, arrow LH indicates the left side in the vehicle width direction (left-right direction), and arrow RH indicates the right side in the vehicle width direction (left-right direction). Furthermore, in the following description, unless otherwise specified, when the front / rear, up / down, and left / right directions are indicated, they refer to the front / rear in the vehicle's front-rear direction, the up / down in the vehicle's up-down direction, and the left / right in the vehicle's left-right direction.

[0019] As shown in Figures 1 and 2, the battery pack 10 comprises a battery module 12 composed of multiple battery cells, a lower case 14 as a lower floor member to which the battery module 12 is fixed, and an upper frame 16 as an upper floor member positioned above the lower case 14. The battery pack 10 also comprises a pair of left and right support members 18 that support the upper frame 16 from below, equipment 20 fixed to the upper frame 16, and an upper cover 22 that covers the battery module 12 and equipment 20 from above.

[0020] The battery module 12 is configured such that a plurality of all-solid-state battery cells are arranged in the front-rear direction, and its overall shape is rectangular parallelepiped. End plates 24 that are fixed to a lower case 14 and an upper frame 16, which will be described later, are respectively fixed to the front end portion and the rear end portion of the battery module 12. In FIG. 2, the end plate 24 is shown in a state where its illustration is omitted. Also, in the present embodiment, two battery modules 12 are vertically connected in a state where they are stacked in the vertical direction. In the following description, the lower battery module 12 may be referred to as the first-stage battery module 12, and the upper battery module 12 may be referred to as the second-stage battery module 12.

[0021] The lower case 14 is formed in a rectangular plate shape that extends in the front-rear direction and the left-right direction with the vertical direction as the thickness direction. A plurality of battery fixing bolt screwing portions 14A to which battery fixing bolts 26 are screwed are provided at the center portion in the left-right direction of the lower case 14. In the present embodiment, four battery fixing bolt screwing portions 14A are provided at the center portion in the left-right direction of the front side portion of the lower case 14, and four battery fixing bolt screwing portions 14A are provided at the center portion in the left-right direction of the rear side portion of the lower case 14.

[0022] Then, four battery fixing bolts 26 are inserted into the end plate 24 fixed to the front end portion of the first-stage battery module 12. And these four battery fixing bolts 26 are respectively screwed into the four battery fixing bolt screwing portions 14A provided at the center portion in the left-right direction of the front side portion of the lower case 14. Similarly, four battery fixing bolts 26 are also inserted into the end plate 24 fixed to the rear end portion of the first-stage battery module 12. And these four battery fixing bolts 26 are respectively screwed into the four battery fixing bolt screwing portions 14A provided at the center portion in the left-right direction of the rear side portion of the lower case 14. Thereby, the first-stage battery module 12 is fixed to the lower case 14.

[0023] Furthermore, four battery fixing bolts 26 are inserted into the end plate 24 fixed to the front end of the second-stage battery module 12. These four battery fixing bolts 26 are then screwed into the upper ends of the four battery fixing bolts 26 on the first-stage battery module 12 side. Similarly, four battery fixing bolts 26 are inserted into the end plate 24 fixed to the rear end of the second-stage battery module 12. These four battery fixing bolts 26 are then screwed into the upper ends of the four battery fixing bolts 26 on the first-stage battery module 12 side. In this way, the second-stage battery module 12 is fixed to the lower case 14.

[0024] Furthermore, the left side of the lower case 14 is provided with two first fixing bolt threaded portions 14B into which the first fixing bolt 34 (described later) is screwed. These two first fixing bolt threaded portions 14B are spaced apart in the front-rear direction. Also, the right side of the lower case 14 is provided with two first fixing bolt threaded portions 14B into which the first fixing bolt 34 (described later) is screwed. These two first fixing bolt threaded portions 14B are spaced apart in the front-rear direction.

[0025] The upper frame 16 is formed in the shape of a rectangular plate, with the vertical direction being the thickness direction and extending in the front-rear and left-right directions. Four frame fixing bolts 28 are inserted into the front end of the upper frame 16. These four frame fixing bolts 28 are screwed into the upper ends of four battery fixing bolts 26 on the second-stage battery module 12 side. Similarly, four frame fixing bolts 28 are inserted into the rear end of the upper frame 16. These four frame fixing bolts 28 are screwed into the upper ends of four battery fixing bolts 26 on the second-stage battery module 12 side. In this way, the upper frame 16 is fixed to the upper part of the second-stage battery module 12. Furthermore, a device 20 is provided on the upper side of the upper frame 16. This device 20 is fixed to the upper part of the upper frame 16. Note that the device 20 may be a device related to charging and discharging the battery module 12, or it may be a device with other functions.

[0026] The left and right pair of support members 18 are positioned on both sides of the battery module 12 in the vehicle width direction, and are fixed to the lower case 14 and upper frame 16 in a state where they are stretched vertically between the lower case 14 and the upper frame 16. These support members 18 consist of a first bracket 30, a second bracket 32, a first fixing bolt 34, a second fixing bolt 36, and a third fixing bolt 38.

[0027] The first bracket 30 is formed in the shape of a rectangular plate, with the left-right direction being the thickness direction and extending in the front-rear and up-down directions. The front end and rear end of the first bracket 30 are each formed with first fixing bolt insertion holes 30A into which the first fixing bolt 34 is inserted.

[0028] The second bracket 32, like the first bracket 30, is formed in the shape of a rectangular plate with the left-right direction as the thickness direction and extending in the front-rear and up-down directions. The front and rear ends of the second bracket 32 ​​each have second fixing bolt insertion holes 32A into which the second fixing bolt 36 is inserted.

[0029] Furthermore, in the left support member 18, two first fixing bolts 34 inserted into the front and rear first fixing bolt insertion holes 30A of the first bracket 30 are screwed into two first fixing bolt threaded portions 14B provided on the left side of the lower case 14. Also, two second fixing bolts 36 inserted into the front and rear second fixing bolt insertion holes 32A of the second bracket 32 ​​are screwed into the upper ends of the two first fixing bolts 34. In addition, two third fixing bolts 38 inserted into the left end of the upper frame 16 are screwed into the upper ends of the two second fixing bolts 36.

[0030] On the right-side support member 18, two first fixing bolts 34 inserted into the front and rear first fixing bolt insertion holes 30A of the first bracket 30 are screwed into two first fixing bolt threaded portions 14B provided on the right side of the lower case 14. Also, two second fixing bolts 36 inserted into the front and rear second fixing bolt insertion holes 32A of the second bracket 32 ​​are screwed into the upper ends of the two first fixing bolts 34. Furthermore, two third fixing bolts 38 inserted into the right-side end of the upper frame 16 are screwed into the upper ends of the two second fixing bolts 36.

[0031] Here, the threaded portion of the first fixing bolt 34 with the first fixing bolt threaded portion 14B is the first deformation starting point portion 18A, which is the deformation starting point when a load due to a side collision is applied. Also, the threaded portion of the second fixing bolt 36 with the first fixing bolt 34 is the second deformation starting point portion 18B, which is the deformation starting point when a load due to a side collision is applied and the vehicle tilts to the other side in the vehicle width direction. The vertical position of this second deformation starting point portion 18B is the same as the threaded portion 26A of the upper and lower battery fixing bolts 26, which are the connecting portion between the first and second battery modules 12. Furthermore, the threaded portion of the third fixing bolt 38 with the second fixing bolt 36 is the third deformation starting point portion 18C, which is the deformation starting point when a load due to a side collision is applied.

[0032] As shown in Figure 2, the upper cover 22 is formed in a hat-shaped cross-section with the lower side open when viewed in cross-section along the vertical and horizontal directions. The lower ends on both sides of the upper cover 22 in the horizontal direction are fixed to both ends of the lower case 14 in the horizontal direction. As a result, the battery module 12, upper frame 16, equipment 20, and the pair of left and right support members 18 are covered by the upper cover 22 from above and from the left and right directions. Here, the parts of the upper cover 22 that face the left and right ends of the upper frame 16 in the horizontal direction are load-receiving parts 22A.

[0033] (Operation and effects of this embodiment) Next, the operation and effects of this embodiment will be described.

[0034] In the event of a side collision involving a vehicle equipped with the battery pack 10 of this embodiment as described above, for example, as shown in Figure 3, when a load F1 to the left is applied to the upper frame 16, the pair of left and right support members 18 tilt to the left, and the upper frame 16 is displaced to one side in the vehicle width direction. Then, the first deformation starting point 18A of the pair of left and right support members 18 undergoes plastic deformation, causing the support members 18 to tilt to the left. This suppresses peeling or fracture at the fixing portion of the support members 18 with the lower case 14, and prevents the upper frame 16 from being displaced upward. In other words, it prevents the battery pack 10 from being displaced upward. Furthermore, by preventing the upper frame 16 from being displaced upward, it is possible to prevent the equipment 20 fixed to the upper part of the upper frame 16 from coming into contact with the upper cover 22.

[0035] Furthermore, when the upper frame 16 is displaced to the left, the left end of the upper frame 16 comes into contact with the load-receiving portion 22A of the upper cover 22, and a reaction load F2 is input from the load-receiving portion 22A toward the upper frame 16. As a result, as shown in Figure 4, the second deformation starting point portion 18B of the pair of left and right support members 18 undergoes plastic deformation. In this way, by deforming the support members 18 so that the second deformation starting point portion 18B becomes a deformation starting point in addition to the first deformation starting point portion 18A, the upward displacement of the upper frame 16 can be further suppressed. That is, the upward displacement of the battery pack 10 can be further suppressed. Here, in the state where the second deformation starting point portion 18B is deformed, the second bracket 32 ​​is displaced so as to tilt to the right relative to the first bracket 30.

[0036] Here, the vertical position of the second deformation initiation point 18B of the support member 18 in the state before the side collision (the state shown in Figure 2) is set to the same position as the vertical position of the connecting portion between the first-section battery module 12 and the second-stage battery module 12. In this configuration, when the second deformation initiation point 18B deforms, it is possible to suppress contact between the second deformation initiation point 18B and the sides of the first-section battery module 12 and the second-section battery module 12.

[0037] Furthermore, when the left end of the upper frame 16 contacts the load-receiving portion 22A of the upper cover 22, and a reaction load F2 is input from the load-receiving portion 22A toward the upper frame 16, the third deformation starting point portion 18C of the support member 18 deforms. In this way, by deforming the support member 18 so that the third deformation starting point portion 18C becomes a deformation starting point in addition to the first deformation starting point portion 18A and the second deformation starting point portion 18B, the upward displacement of the upper frame 16 can be further suppressed. In other words, the upward displacement of the battery pack 10 can be further suppressed.

[0038] Furthermore, as shown in Figure 1, in the battery pack 10 of this embodiment, end plates 24 are fixed to the front and rear ends of the battery module 12, respectively. The end plates 24 are also fixed to the lower case 14 and the upper frame 16, respectively. In this configuration, because the upper frame 16 is fixed to the end plates 24 of the battery module 12 and the lower case 14, upward displacement of the upper frame 16 can be further suppressed. In particular, since all-solid-state batteries have a highly rigid structure due to the strong restraining pressure, upward displacement of the upper frame 16 can be further suppressed.

[0039] In this embodiment, the first deformation initiation point 18A was the screwed portion of the first fixing bolt 34 with the first fixing bolt screwed portion 14B, but the present invention is not limited thereto. The first deformation initiation point 18A only needs to be configured to be the initiation point of deformation, and for example, a structure with reduced rigidity may be used, grooves or holes may be provided, or the material used may be changed. This can also be applied to the second deformation initiation point 16B and the third deformation initiation point 18C.

[0040] Furthermore, although this embodiment describes an example in which the battery module 12 has a plurality of battery cells that are all-solid-state batteries, the present invention is not limited thereto. For example, the battery module 12 may have a configuration in which a plurality of battery cells containing an electrolyte are included.

[0041] Furthermore, although this embodiment describes an example in which the battery module 12 is fixed to the lower case 14 and upper frame 16 via an end plate 24, the present invention is not limited thereto. For example, the battery module 12 may be fixed to the lower case 14 and upper frame 16 by a fixing structure with a different configuration from the end plate 24.

[0042] Furthermore, although this embodiment describes an example in which the support member 18 is deformed so that the second deformation starting point 18B and the third deformation starting point 18C become deformation starting points in addition to the first deformation starting point 18A, the present invention is not limited thereto. Whether or not to provide the second deformation starting point 18B and the third deformation starting point 18C can be appropriately determined by considering the configuration around the battery pack 10, etc.

[0043] Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above, and can be implemented in various other ways without departing from the spirit of the invention. [Explanation of symbols]

[0044] 10 battery packs 12 Battery Modules 14. Lower case (lower floor component) 16. Upper frame (upper floor member) 18 Support Member 18A First deformation starting point 18B Second deformation starting point 18C Third deformation starting point 22A Load-bearing section 24 End Plates

Claims

1. A battery module comprising multiple battery cells, The lower floor member to which the battery module is fixed, An upper floor member positioned above the lower floor member of the vehicle, Support members are positioned on both sides in the vehicle width direction relative to the battery module, and are fixed to the lower floor member and the upper floor member in a manner that spans the vehicle vertically between the lower floor member and the upper floor member, supporting the upper floor member from below. A first deformation initiation point is provided on the side of the support member that is fixed to the lower floor member, and which serves as the deformation initiation point when the support member tilts to one side in the vehicle width direction. A battery pack is included.

2. On the outer side in the vehicle width direction relative to the upper floor member, a load-receiving portion is provided that contacts the upper floor member when it is displaced to one side in the vehicle width direction. The battery pack according to claim 1, wherein a second deformation initiation point is provided in the intermediate portion of the support member in the vehicle's vertical direction between the first deformation initiation point and the upper floor member, which serves as the deformation initiation point when the upper floor member tilts to the other side in the vehicle's width direction after contacting the load receiving portion.

3. Multiple battery modules are stacked in the vertical direction of the vehicle and connected in the vertical direction of the vehicle. The battery pack according to claim 2, wherein the position of the second deformation starting point in the vehicle vertical direction is set to the same position as the position of the connecting portion between one battery module and the other battery module in the vehicle vertical direction.

4. The battery pack according to claim 2 or 3, wherein the support member is provided with a third deformation initiation point on the side of the fixing portion with the upper floor member, which serves as the deformation initiation point after the upper floor member comes into contact with the load receiving portion.

5. Each of the aforementioned battery cells is a solid-state battery and is arranged in a line in the front-to-rear direction of the vehicle. End plates are fixed to the front and rear ends of the battery module, respectively. The battery pack according to claim 1, wherein the end plates are fixed to the lower floor member and the upper floor member, respectively.

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