Battery pack construction

Abstract

The battery pack structure of the present application includes a battery module and a case that houses the battery module. The case includes a lower case disposed on a lower side of the battery module. In addition, the case includes an upper case disposed on an upper side with respect to the lower case and formed of a fiber-reinforced resin.

Description

Technical Field

[0001] This invention relates to a battery pack structure. Background Technology

[0002] Japanese Patent Application Publication No. 2021-070386 discloses a vehicle battery housing structure for housing a battery mounted in a vehicle. In this vehicle battery housing structure, a battery module housing is formed by a first side member and a second side member arranged opposite to each other. One or both of the first side member and the second side member have a skeleton hollow portion located on the side of the battery module and a lower hollow portion located on the lower side of the battery module, and a gap hollow portion formed between the housing bottom of the battery module housing and the lower hollow portion. Furthermore, by integrally forming the skeleton hollow portion, the gap hollow portion, and the lower hollow portion, both protection of the vehicle battery and space saving can be achieved.

[0003] However, in a battery pack having a battery module and a housing for housing the battery module, it is preferable to suppress the formation of useless space between the battery module and the housing, but in the configuration described in Japanese Patent Application Publication No. 2021-070386, there is still room for improvement in this respect. Summary of the Invention

[0004] Considering the above facts, the object of the present invention is to obtain a battery pack structure that can suppress the formation of useless space between the battery module and the housing.

[0005] The battery pack structure of the first embodiment includes: a battery module; a lower housing disposed below the battery module and forming part of the housing for housing the battery module; and an upper housing disposed above the lower housing and formed using fiber-reinforced resin, forming another part of the housing.

[0006] In the first embodiment of the battery pack structure, the battery module is housed in a casing. This casing is configured to include a lower casing and an upper casing disposed above the lower casing. Here, the upper casing is formed using fiber-reinforced resin. In this configuration, for example, compared to a configuration where the upper casing is formed of a metal plate, the shape of the upper casing is less restrictive. Therefore, the formation of unusable space between the battery module and the casing (upper casing) can be suppressed.

[0007] The second battery pack structure is formed as follows: based on the first battery pack structure, the upper housing has a side wall portion that covers the battery module on the side side, and the inclination angle of the side wall portion relative to the vertical direction is set to 0.5° or less.

[0008] In the second battery pack structure, the upper casing is formed using fiber-reinforced resin, thereby allowing the tilt angle of the sidewall portion of the upper casing relative to the vertical direction to be set to 0.5° or less. This prevents the formation of unusable space between the battery module and the sidewall portion of the upper casing.

[0009] The battery pack structure involved in this invention has the excellent effect of suppressing the formation of useless space between the battery module and the casing. Attached Figure Description

[0010] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements, wherein,

[0011] Figure 1 This is a schematic side view of a vehicle that uses the battery pack structure of this embodiment.

[0012] Figure 2 This is a schematic top view of the lower part of a vehicle that uses the battery pack structure of this embodiment.

[0013] Figure 3 This is a 3D view of the battery pack and other components, viewed from the left front.

[0014] Figure 4 It means along Figure 3 The cross-sectional view of the battery pack casing shown is a section cut along line 4-4.

[0015] Figure 5 It means along Figure 3 The cross-sectional view of the battery pack casing shown is cut along line 5-5.

[0016] Figure 6 This is a schematic diagram used to illustrate the manufacturing process of the upper shell. Detailed Implementation

[0017] use Figures 1-6 The vehicle 10, which utilizes the battery pack structure according to embodiments of the present invention, will be described. Furthermore, in the accompanying drawings, arrow FR appropriately indicates the front side 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). Additionally, in the following description, unless otherwise specified, the directions of front-back, up-down, and left-right refer to front-back in the front-back direction, up-down in the up-down direction, and left-right in the left-right direction.

[0018] like Figure 1 and Figure 2As shown, the vehicle 10 of this embodiment includes a front axle 14 that drives the front wheels 12, a rear axle 18 that drives the rear wheels 16, and a battery pack 20 that stores the power supplied to the front axle 14 and the rear axle 18.

[0019] The front axle 14 is configured to include a motor 22, an inverter 24, and various devices 26. The front axle 14 is supported by a front member 28 located at the front of the vehicle 10.

[0020] The rear axle 18 is the same as the front axle 14, and is configured to include a motor 30, an inverter 32, and various devices 34. The rear axle 18 is supported by a rear member 36 located at the rear of the vehicle 10.

[0021] like Figure 1 , Figure 2 as well as Figure 3 As shown, the battery pack 20 is disposed in the center of the vehicle 10 in the width direction. The battery pack 20 includes a first battery pack section 38, which is formed as a cuboid with its long side in the longitudinal direction, and whose front portion forms the central portion in the longitudinal direction. Additionally, the battery pack 20 includes a second battery pack section 40, which is formed as a cuboid with its long side in the left-right direction, and whose rear portion forms the rear portion of the battery pack 20.

[0022] The front end of the first battery pack 38 is disposed adjacent to the front axle 14 in the longitudinal direction. Furthermore, most of the first battery pack 38 is disposed in the center of the cab 42 in the vehicle width direction. In this embodiment, vehicle seats 44 are provided on both sides of the rear portion 38R of the first battery pack 38 in the left-right direction. Moreover, the dimension of the rear portion 38R of the first battery pack 38 in the vehicle width direction is set to be smaller than the dimension of the front portion 38F of the first battery pack 38 in the vehicle width direction.

[0023] The rear end of the second battery pack 40 is disposed adjacent to the rear axle 18 in the longitudinal direction. The dimension of the second battery pack 40 in the vehicle width direction is set to be larger than the dimension of the first battery pack 38 in the vehicle width direction. In addition, the dimension of the second battery pack 40 in the vertical direction is set to be larger than the dimension of the first battery pack 38 in the vertical direction.

[0024] like Figure 2 , Figure 3 , Figure 4 as well as Figure 5 As shown, the battery pack 20 described above is configured to include a housing 46 that forms the outline of the battery pack 20 and a plurality of battery modules 48 housed within the housing 46.

[0025] The housing 46 includes: a lower housing 50 extending along the lower part of the vehicle 10 in the longitudinal and lateral directions; and an upper housing 52 mounted on the lower housing 50 from above. A space is formed between the lower housing 50 and the upper housing 52 for arranging a plurality of battery modules 48. Furthermore, as an example, the battery module 48 is configured to have a plurality of battery cells stacked on top of each other. Here, in the space between the lower housing 50 and the upper housing 52, there is a portion of the lower housing 50 where a plurality of battery modules 48 are supported in a stacked manner in the vertical direction.

[0026] As an example, the lower housing 50 is formed using an extruded material, specifically an aluminum alloy. This lower housing 50 is joined to the front beam 28 and rear beam 36 using bolts or the like, thus functioning as a component to ensure the rigidity of the lower part of the vehicle 10. Furthermore, the lower housing 50 of this embodiment has a hollow structure (see reference). Figure 5 ).

[0027] As an example, the upper housing 52 is formed using fiber-reinforced resins such as CFRP and GFRP. In this upper housing 52, the portion corresponding to the first battery pack portion 38 has an upper wall portion 52A extending in the front-back and left-right directions with the vertical direction as its thickness direction, and a pair of left and right side wall portions 52B extending downwards from both ends of the upper wall portion 52A in the left-right direction. Furthermore, the portion of the upper housing 52 corresponding to the first battery pack portion 38 has a front wall portion 52C, which extends downwards from the front end of the upper wall portion 52A, and its two ends in the left-right direction are connected to the pair of left and right side wall portions 52B.

[0028] Furthermore, the upper housing 52, corresponding to the second battery pack section 40, includes an upper wall portion 52D extending in the front-back and left-right directions with the thickness direction being vertical, and a pair of left and right sidewall portions 52E extending downward from both ends of the upper wall portion 52D in the left-right direction. Additionally, the upper housing 52, corresponding to the second battery pack section 40, includes a front wall portion 52F extending downward from the front end of the upper wall portion 52D, and its left and right ends are connected to the pair of left and right sidewall portions 52E. This front wall portion 52F is connected in the upper housing 52 to the rear end of the upper wall portion 52A and the rear end of the pair of left and right sidewall portions 52B, which form the portion corresponding to the first battery pack section 38. Finally, the upper housing 52, corresponding to the second battery pack section 40, includes a rear wall portion 52G extending downward from the rear end of the upper wall portion 52D, and its left and right ends are connected to the pair of left and right sidewall portions 52E.

[0029] A front connector module 54 and a rear connector module 56 for connecting various wiring are mounted on the upper housing 52. The front connector module 54 is mounted on the front end of the upper wall portion 52A. The rear connector module 56 is mounted on the upper wall portion 52D. Furthermore, the front connector module 54 is connected to connectors for wiring that connects to the inverter 24 constituting the front axle 14, various devices 26, and other devices 58. Similarly, the rear connector module 56 is connected to connectors for wiring that connects to the inverter 32 constituting the rear axle 18 and various devices 34.

[0030] like Figures 1-5 As shown, in the embodiment described above, the upper housing 52, which constitutes part of the housing 46, is formed using fiber-reinforced resin. In this configuration, for example, compared to a configuration where the upper housing 52 is formed from a metal plate, it is less constrained by the shape of the upper housing 52. Therefore, the formation of useless space between the multiple battery modules 48 and the housing 46 (upper housing 52) can be suppressed. Furthermore, by suppressing the enlargement of the upper housing 52, other components, wiring, and piping can be easily arranged along the outer side of the upper housing 52. Additionally, by using fiber-reinforced resin to form the upper housing 52, the increase in the weight of the battery pack 20 can be suppressed.

[0031] Furthermore, in this embodiment, the battery pack 20 is positioned near the roll axis of the vehicle 10. This reduces the inertial torque generated at the vehicle's roll axis. Additionally, in this embodiment, the battery pack 20 is not positioned below the vehicle seat 44. This lowers the hip point of the occupant sitting in the vehicle seat 44. Moreover, the configuration and arrangement of the battery pack 20 in this embodiment enable a vehicle 10 with a low vehicle height and an aesthetically pleasing exterior design.

[0032] Furthermore, in this embodiment, the lower housing 50 can function as a component for ensuring the rigidity of the lower part of the vehicle 10. Additionally, by making the lower housing 50 hollow, it is possible to contribute to the weight reduction of the vehicle 10. Furthermore, the lower housing 50 can also function as a road surface interference protection component for the vehicle 10. Therefore, additional protective components for road surface interference can be omitted. Moreover, by adjusting the volume of the hollow portion of the lower housing 50 without changing the vertical dimensions of the lower housing 50, the amount of energy absorbed due to deformation of the lower housing 50 can be adjusted.

[0033] Furthermore, in this embodiment, the front connector module 54 and the rear connector module 56 are respectively mounted on the front and rear of the battery pack 20. This increases the flexibility in the mounting layout of devices that need to be connected to the battery pack 20. Additionally, it helps to prevent the charging path from the charging port to the battery pack 20 (battery module 48) from becoming too long.

[0034] Here, in Figure 6 The diagram schematically illustrates an apparatus for molding the upper housing 52. As shown in the figure, as an example, the upper housing 52 is molded through the following steps: First, a pre-impregnated material 60, consisting of resin-impregnated fiber sheets, is laminated along the surface of a mold 62. Next, a bag film 64 is placed over the pre-impregnated material 60 laminated along the surface of the mold 62. Then, pressure is applied between the bag film 64 and the mold 62. This process molds the upper housing 52. This molding method is referred to as oven molding. Alternatively, the upper housing 52 can also be molded using an autoclave, where pressure is applied between the bag film 64 and the mold 62, and pressure is applied around the bag film 64 and the mold 62. In this way, when the upper housing 52 is molded using either oven molding or autoclave molding, for example, the inclination angle of the sidewall portions 52B and 52E of the upper housing 52 relative to the vertical direction can be set to 0.5° or less. This prevents the formation of useless space between the battery module 48 and the side wall portions 52B and 52E of the upper housing 52.

[0035] The present invention has been described above as one embodiment, but the present invention is not limited to the above description. Of course, various modifications other than those described above can be made without departing from its spirit.

Claims

1. A battery pack structure, characterized in that, The battery pack structure includes: Battery module; A lower housing, disposed below the battery module, and forming part of the housing for receiving the battery module; and The upper housing, disposed on the upper side relative to the lower housing, and formed using fiber-reinforced resin, constitutes another part of the housing.

2. The battery pack structure according to claim 1, characterized in that, The upper housing has a sidewall portion that covers the side of the battery module. The inclination angle of the sidewall relative to the vertical direction is set to 0.5° or less.

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