Battery pack

Abstract

To provide a battery pack that can protect a battery from a side collision and can be made smaller and lighter.SOLUTION: A battery pack 10 includes: a battery module 20; a battery case 30; and wiring 60 arranged inside the battery case 30. The battery case 30 includes: a bottom plate 31; side walls 32 standing upright from an outer edge of the bottom plate 31; and cross members 33 arranged between the opposing left and right side walls 32. The cross members 33 include: a cross member body 52 formed by aluminum die casting together with at least a part of the bottom plate 31 and the side walls 32; and a reinforcing plate 53 installed on an upper surface of the cross member body 52. The cross member body 52 has a recess 51 in a center of the battery case 30. The wiring 60 is arranged in a space 55 formed between the cross member body 52 and the reinforcing plate 53.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a battery pack that can be mounted in a vehicle. [Background technology]

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into electrification technologies is being conducted in vehicles to reduce CO2 emissions and improve energy efficiency.

[0003] Batteries play an important role in electrification technology. Because batteries are high-voltage components, they need to be protected from impacts. However, when batteries are installed in vehicles, there is a possibility that a large load may be input to the battery in the event of a collision. Until now, battery cases have been made of steel to protect the battery from collision loads.

[0004] Incidentally, reducing the weight of a vehicle is important to extend the vehicle's driving range. For example, Patent Document 1 describes the use of a drawn aluminum alloy, a material lighter than steel, for part of the side member of the battery case. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-97816 A Summary of the Invention [Problem to be solved by the invention]

[0006] In addition, inside the battery case, cooling pipes, power lines, signal lines, and other wiring are arranged. If these pipes and wiring are arranged above the battery, the height of the battery pack will increase. If the battery pack is arranged under the floor of the vehicle, if the battery pack is too tall, it may protrude into the passenger compartment, making it difficult to ensure a sufficiently spacious passenger compartment.

[0007] The present invention provides a battery pack that can protect a battery from a side collision and can be made smaller and lighter. [Means for solving the problem]

[0008] The present invention relates to A battery module; a battery case that houses the battery module; A battery pack comprising: wiring or piping disposed inside the battery case, The battery case includes: Bottom and A side wall extending from an outer edge of the bottom surface; A cross member is disposed across the opposing left and right side walls, The cross member is a member body formed by aluminum die casting together with at least a portion of the bottom surface and the side wall; a reinforcing plate disposed on an upper surface of the member body; The member body has a recess in a center portion of the battery case, The wiring or piping is disposed in a space formed between the member body and the reinforcing plate. Effect of the Invention

[0009] According to the present invention, the height and weight of the battery pack can be reduced, and further, the input load of a side collision can be appropriately received by the battery case. [Brief description of the drawings]

[0010] [Figure 1] 2 is a perspective view of a battery case 30 constituting the battery pack 10. FIG. [Diagram 2] 4 is an enlarged view showing a space 55 of a first cross member 331. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a battery pack of the present invention will be described with reference to the drawings.

[0012] As shown in Fig. 1, the battery pack 10 includes a plurality of battery modules 20 and a battery case 30 that houses the plurality of battery modules 20. Note that Fig. 1 illustrates only two battery modules 20, and does not illustrate the other battery modules 20. The number and arrangement of the battery modules 20 housed in the battery case 30 can be set as appropriate.

[0013] The battery case 30 includes a rectangular bottom plate 31 on which a plurality of battery modules 20 are mounted, a side wall 32 standing upright from the outer edge of the bottom plate 31, and a plurality of cross members 33.

[0014] The side wall 32 includes a front plate 321 that constitutes the front wall of the battery case 30, a rear plate 322 that constitutes the rear wall, a left side plate 333L that constitutes the left wall, and a right side plate 333R that constitutes the right wall.

[0015] The cross member 33 includes a first cross member 331 and a second cross member 332 having a different shape from the first cross member 331. The cross member 33 of this embodiment has two first cross members 331 and four second cross members 332, and the second cross members 332 and the first cross members 331 are alternately arranged from the front, and the two second cross members 332 are arranged behind the second first cross member 331. The number and arrangement of the first cross members 331 and the second cross members 332 can be changed as appropriate.

[0016] Referring also to FIG. 2, the first cross member 331 comprises a cross member body 52 having a recess 51 provided in the center, and a reinforcing plate 53 disposed on the upper surface of the cross member body 52 so as to cover the recess 51.

[0017] The cross member body 52 has two plate-like members that connect the left side plate 333L and the right side plate 333R and are arranged facing each other with a predetermined gap in the front-rear direction. The cross member body 52 has a plurality of (four in this embodiment) nut portions 335 formed between the plate-like members on both the left and right sides of the recess 51.

[0018] The reinforcing plate 53 mounted on the upper surface of the cross member main body 52 is a plate-shaped member made of high tensile steel, and its length in the left-right direction is shorter than that of the cross member main body 52. ​​The reinforcing plate 53 is fastened with a bolt 337 to a nut portion 335 provided on the cross member main body 52, and is fixed to the cross member main body 52. ​​The width (front-rear length) of the reinforcing plate 53 is approximately equal to the width (front-rear length) of the cross member main body 52.

[0019] 1, the second cross member 332 is configured to incline from the left side plate 333L and the right side plate 333R so that the height decreases toward the center. The height of the center of the second cross member 332 is approximately equal to the height of the recess 51 of the cross member main body 52 constituting the first cross member 331.

[0020] The second cross member 332 is not provided with a reinforcing plate 53. The reinforcing plate 53 is provided only on some of the multiple cross members 33, that is, on the first cross member 331.

[0021] The battery case 30 is formed from an aluminum alloy containing aluminum, except for the reinforcing plate 53 of the first cross member 331. More specifically, the bottom plate 31, the side wall 32, the cross member body 52 of the first cross member 331, and the second cross member 332 of the battery case 30 are formed by aluminum die casting. Aluminum die casting is performed by melting an aluminum alloy, filling it into a mold at high speed using a die casting machine, and then applying high pressure.

[0022] The bottom plate 31, side walls 32, cross member body 52 of the first cross member 331, and second cross member 332 of the battery case 30 may be integrally molded, or these may be divided into a plurality of parts, such as two or three parts, and then joined together. However, the cross member body 52 of the first cross member 331 is formed by aluminum die casting together with at least a portion of the bottom plate 31 and at least a portion of the side walls 32.

[0023] In this way, the battery case 30 is formed using an aluminum alloy that is lighter than iron, and therefore the battery case can be made lighter than a battery case that uses an iron plate material. In addition, since most of the battery case 30 is formed from aluminum die casting, the process of joining sheet metal members together can be omitted or simplified.

[0024] In recent years, the battery pack 10 has become larger and heavier, so the cross member 33, which is a frame member of the battery case 30, is required to have high strength. In order to reduce the weight of the battery case 30, if the battery case 30 is changed from iron to aluminum alloy, the strength decreases at the same thickness, and in order to obtain the same strength as that of high tensile steel with aluminum alloy, it is necessary to increase the height of the cross member 33. However, if the height of the cross member 33 is increased, the battery pack 10 protrudes toward the passenger compartment. Therefore, by using only the reinforcing plate 53 as high tensile steel and using aluminum alloy for most of the battery case 30, the load during a side collision can be received by both the cross member main body 52 and the second cross member 332 of the first cross member 331 formed integrally with the bottom plate 31, and the reinforcing plate 53 provided on the first cross member 331.

[0025] Inside the battery case 30, there are arranged refrigerant piping for supplying refrigerant to a water jacket that cools the battery modules 20 and discharging the refrigerant from the water jacket, and / or wiring for connecting the battery modules 20 inside the battery case 30 to DC lines outside the battery case 30. Hereinafter, these wirings or pipings are referred to as wiring 60. If these wirings 60 are routed above the cross member 33, the wirings 60 will protrude upward, causing the battery pack 10 to protrude into the passenger compartment.

[0026] Therefore, the wiring 60 is arranged in the space 55 formed between the cross member main body 52 and the reinforcing plate 53. More specifically, the wiring 60 is arranged in the space 55 formed between the recess 51 of the cross member main body 52 and the reinforcing plate 53. This makes it possible to prevent the wiring 60 from protruding upward.

[0027] In addition, since the first cross member 331 has approximately the same height regardless of the left-right position, the position of the center of the cross section in the height direction is approximately constant. If the position of the center of the cross section in the height direction differs depending on the left-right position, a moment will be generated when an impact load is input, and further reinforcement will be required. By providing a recess 51 in the cross member main body 52 constituting the first cross member 331 and routing the wiring 60 in the space 55 formed between the recess 51 and the reinforcing plate 53, the height of the center of the cross section can be set to approximately the same regardless of the left-right position of the first cross member 331.

[0028] Furthermore, since the height of the central portion of the second cross member 332 and the height of the recess 51 of the cross member main body 52 constituting the first cross member 331 are approximately equal, even if the wiring 60 is a long member extending in the fore-and-aft direction across the first cross member 331 and the second cross member 332, it can be arranged in the fore-and-aft direction within the battery pack 10 without changing its position in the up-and-down direction.

[0029] 2, it is preferable that the reinforcing plate 53 is provided with a fixing portion 53a for mounting the electronic component. This allows the bracket for mounting the electronic component to be made smaller. The fixing portion 53a may be, for example, a female thread portion formed in the reinforcing plate 53, or a nut portion welded to the reinforcing plate 53. The bracket for mounting the electronic component may be fastened to the nut portion 335 by a bolt 337.

[0030] Moreover, a rib 34 extending in the front-rear direction is preferably formed in the center of the battery case 30 in the left-right direction. This can improve the strength of the battery case 30. Moreover, the rib 34 preferably includes a nut portion 35. The nut portion 35 can be used to fasten a bracket or the like that fixes the wiring 60.

[0031] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. Furthermore, the components in the above-mentioned embodiments may be arbitrarily combined within the scope of the invention.

[0032] This specification describes at least the following items. Note that, in parentheses, corresponding components and the like in the above-mentioned embodiment are shown, but the present invention is not limited to these.

[0033] (1) a battery module (battery module 20); a battery case (battery case 30) that houses the battery module; A battery pack (battery pack 10) including wiring or piping (wiring 60) disposed inside the battery case, The battery case includes: Bottom surface (bottom plate 31) and A side wall (side wall 32) extending from the outer edge of the bottom surface; A cross member (cross member 33) is disposed across the opposing left and right side walls, The cross member is a member body (cross member body 52) formed by aluminum die casting together with at least a portion of the bottom surface and the side walls; A reinforcing plate (reinforcing plate 53) is provided on the upper surface of the member body, The member body has a recess (recess 51) in the center of the battery case, The wiring or the piping is disposed in a space (space 55) formed between the member body and the reinforcing plate.

[0034] According to (1), the cross member is formed by aluminum die casting, thereby making it possible to reduce the weight of the battery pack. In addition, by installing a reinforcing plate on the upper surface of the cross member body, the load during a side collision can be received by both the cross member formed integrally with the bottom surface and the reinforcing plate. This allows the battery pack to appropriately receive the load during a side collision while keeping the height of the battery pack low. However, if the center of the cross section is shifted up or down depending on the position in the vehicle width direction, it is necessary to reinforce the part that is shifted up or down in order to receive the side collision load. By forming a recess in the member body and forming a space through which wiring or piping can pass by using a reinforcing plate, the center of the cross section does not shift up or down depending on the position in the vehicle width direction, and the input load during a side collision can be more appropriately received.

[0035] (2) A battery pack according to (1), The cross member is provided in plurality, The reinforcing plate is attached to only a portion (first cross member 331) of the multiple cross members of the battery pack.

[0036] According to (2), by arranging the reinforcing plate only in the necessary parts, an increase in the number of parts can be suppressed, and productivity can be improved.

[0037] (3) A battery pack according to (1), The battery pack, wherein the reinforcing plate is formed from high tensile steel.

[0038] According to (3), by using high-tensile steel, strength can be ensured even with a small cross-section.

[0039] (4) A battery pack according to (3), The reinforcing plate is fixed to the cross member with a bolt (bolt 337).

[0040] According to (4), since the wiring or piping can be fixed after installation, productivity is improved.

[0041] (5) A battery pack according to (1), The reinforcing plate is provided with a fixing portion (fixing portion 53a) for mounting an electronic component.

[0042] According to (5), by using a reinforcing plate to mount electronic components, the bracket for mounting the electronic components can be made smaller. [Explanation of symbols]

[0043] 10 Battery pack 20 Battery Module 30 Battery case 31 Bottom plate (bottom surface) 32 Side wall 33 Cross member 51 Recess 52 Cross member body (member body) 53 Reinforcement plate 53a Fixed part 55 Space section 60 Wiring (piping) 331 First cross member 337 Volts

Claims

1. A battery module; a battery case that houses the battery module; A battery pack comprising: wiring or piping disposed inside the battery case, The battery case includes: Bottom and A side wall extending from an outer edge of the bottom surface; A cross member is disposed across the opposing left and right side walls, The cross member is a member body formed by aluminum die casting together with at least a portion of the bottom surface and the side wall; a reinforcing plate disposed on an upper surface of the member body; The member body has a recess in a center portion of the battery case, The wiring or the piping is disposed in a space formed between the member body and the reinforcing plate.

2. 2. The battery pack according to claim 1, The cross member is provided in plurality, The reinforcing plate is attached to only some of the cross members.

3. 2. The battery pack according to claim 1, The battery pack, wherein the reinforcing plate is formed from high tensile steel.

4. 4. The battery pack according to claim 3, The reinforcing plate is fixed to the cross member by bolts.

5. 2. The battery pack according to claim 1, The reinforcing plate is provided with a fixing portion for attaching an electronic component.

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