Tray for battery pack and battery pack provided with the tray

Abstract

This tray for a battery pack mounted on a vehicle comprises: at least one battery cell; a bottom plate part on which at least one battery cell is placed; a pair of side members fixed to the bottom plate part so as to be spaced apart from each other in a vehicle width direction, the pair of side members being provided so as to extend in a front-rear direction of the vehicle; and at least one cross member provided so as to extend in the vehicle width direction. The at least one cross member overlaps with a position of a center part in a height direction of the at least one battery cell, which is a direction perpendicular to the bottom plate part, and is fixed to each of the pair of side members in a state of being welded to each of the pair of side members.

Description

Battery pack tray and battery pack including this tray

[0001] The present disclosure relates to a tray for a battery pack and a battery pack including the tray.

[0002] Patent Document 1 describes a battery tray that includes a pair of side members that are provided on the left and right sides of the vehicle in the vehicle width direction and fixed to the vehicle, and a cross member that extends in the vehicle width direction.

[0003] Japanese Patent Application Laid-Open No. 2022-111787

[0004] In the battery tray of Patent Document 1, both ends of the cross member are not fixed to the side members, so when a collision load is applied to the side members, the cross member may shift relative to the side members, which could result in unintended deformation of the battery pack.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a battery pack tray that can reduce the risk of unintended deformation due to collision load during a vehicle collision, and a battery pack including this tray.

[0006] In order to achieve the above-mentioned object, the battery pack tray of the present disclosure is a battery pack tray to be mounted on a vehicle, and comprises at least one battery cell, a bottom plate portion on which the at least one battery cell is placed, and a pair of side members fixed to the bottom plate portion with a gap in the vehicle width direction of the vehicle, the pair of side members extending in the fore-and-aft direction of the vehicle, and at least one cross member extending in the vehicle width direction, wherein the at least one cross member overlaps with the position of the center of the at least one battery cell in the height direction, which is a direction perpendicular to the bottom plate portion, and is fixed to each of the pair of side members in a welded state.

[0007] According to the battery pack tray of the present disclosure, the cross member is welded and fixed to each of the pair of side members, so that even if a collision load is applied to the cross member during a vehicle collision, the cross member is less likely to shift relative to the side members, thereby reducing the risk of unintended deformation of the tray. Furthermore, when an impact load is applied to the tray during a vehicle collision, particularly a side collision, the cross member receives the impact load in its longitudinal direction. However, if the cross member is positioned either downward or upward in the vertical direction, the cross member may bend due to the impact load. In contrast, because the cross member is positioned in a vertical direction that overlaps with the center of the battery module, it is less likely to bend when a collision load is applied, thereby reducing the risk of unintended deformation of the tray.

[0008] 1 is a schematic diagram illustrating a configuration of a battery pack according to an embodiment of the present disclosure in a state where the case lid is removed from the case tray to allow the interior of the case to be seen;

[0009] Hereinafter, a battery pack tray according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment described below shows one aspect of the present disclosure, but does not limit the present disclosure and can be modified as desired within the scope of the technical concept of the present disclosure.

[0010] The battery pack 1 according to one embodiment of the present disclosure shown in FIG. 1 is a battery pack mounted on a vehicle. The vehicle may be a battery electric vehicle (BEV) powered by a motor, or an electric vehicle such as a hybrid vehicle (HV) or a fuel cell vehicle (FCV) powered by an engine and a motor. A hybrid vehicle may be, for example, a plug-in hybrid vehicle (PHEV, PHV) that can be charged from an external power source or can externally supply power to an external device, but is not limited to a plug-in hybrid vehicle. The battery pack 1 may be mounted inside or outside the vehicle (for example, under the floor).

[0011] The battery pack 1 includes a case 2 and a battery module 5 housed within the case 2. The case 2 includes a tray 3 on which the battery module 5 is placed, and a lid 4 that combines with the tray 3 on which the battery module 5 is placed to seal the battery module 5 inside the case 2. While Fig. 1 illustrates a configuration in which multiple battery modules 5 are housed, this configuration is not limited, and it is sufficient that at least one battery module is housed. Furthermore, what is housed within the case 2 is not limited to a battery module made up of multiple battery cells, and at least one battery cell may be housed within the case 2.

[0012] The tray 3 includes a bottom plate 11 on which the battery module 5 is placed, a pair of side members 12a, 12b that are fixed to the bottom plate 11 with a gap between them in the vehicle width direction when the battery pack 1 is installed in the vehicle and that extend in the front-to-rear direction of the vehicle, and a cross member 13 that extends in the vehicle width direction. The cross member 13 is fixed to each of the side members 12a, 12b by being welded to each of the side members 12a, 12b. While Fig. 1 shows a configuration with two cross members 13, only one cross member 13 or three or more cross members 13 may be provided.

[0013] The side members 12a, 12b may have a plate shape. The tray 3 may further include a plate-shaped front member 14a and a plate-shaped rear member 14b fixed to the bottom plate portion 11 at a distance from each other in the longitudinal direction of the vehicle and extending in the vehicle width direction, with the front member 14a connected to the front ends of the side members 12a, 12b, and the rear member 14b connected to the rear ends of the side members 12a, 12b. The side members 12a, 12b, the front member 14a, and the rear member 14b configured in this manner form side plates provided along the periphery of the bottom plate portion 11 of the tray 3.

[0014] A pair of plate-shaped mounting frames 15a, 15b may be fixed to the pair of side members 12a, 12b, respectively, so as to protrude outward in the vehicle width direction from the pair of side members 12a, 12b. Each of the mounting frames 15a, 15b is configured to be engageable with a fastening jig 16, such as a bolt, in order to fix the tray 3 to the vehicle body (e.g., a pair of floor side members extending in the front-rear direction of the vehicle).

[0015] 2 , if the direction perpendicular to the bottom plate 11 is defined as the height direction, the cross member 13 is provided in a position in the height direction that overlaps with the center position CP of the battery module 5 in the height direction. The cross member 13 is preferably provided so that there is a gap between the bottom plate 11 and its lower surface 13a, which faces the bottom plate 11, i.e., so that it does not come into contact with the bottom plate 11. The cross member 13 is also preferably provided so that there is a gap between the lid 4 and its upper surface 13b, which faces the lid 4, i.e., so that it does not come into contact with the lid 4.

[0016] The tray 3 may further include reinforcing frames 17a, 17b fixed to the side members 12a, 12b and the mounting frames 15a, 15b, respectively. The reinforcing frames 17a, 17b each include a surface 17a1, 17b1 that forms an acute angle with the bottom plate portion 11 and faces outward in the vehicle width direction. The reinforcing frames 17a, 17b may have any configuration as long as they include such a surface 17a1, 17b1. A plurality of plate-shaped (e.g., rib-shaped) reinforcing frames 17a, 17b may be provided at intervals along the length of the mounting frames 15a, 15b (the direction perpendicular to the plane of FIG. 2 ), or triangular prism-shaped reinforcing frames 17a, 17b may each be provided. FIG. 2 illustrates reinforcing frames 17a, 17b having the former configuration.

[0017] In the tray 3 of the battery pack 1, the cross member 13 is fixed by welding to each of the side members 12a and 12b. This prevents the cross member 13 from shifting relative to the side members 12a and 12b even when a collision load is applied to the cross member 13 during a vehicle collision, thereby reducing the risk of unintended deformation of the tray 3. Furthermore, when an impact load is applied to the tray 3 during a vehicle collision, particularly a side collision, the cross member 13 receives the impact load in its longitudinal direction. However, if the cross member 13 is positioned either downward or upward in the height direction, the cross member 13 may bend due to the impact load. In contrast, because the cross member 13 is positioned in a height direction that overlaps the height center position CP of the battery module 5, it is less likely to bend when a collision load is applied, thereby reducing the risk of unintended deformation of the tray 3.

[0018] When the tray 3 is equipped with mounting frames 15a, 15b and reinforcing frames 17a, 17b, the reinforcing frames 17a, 17b have surfaces 17a1, 17b1 having the above-described configuration, which allow the collision load of a side impact to be transmitted in a direction perpendicular to each of the surfaces 17a1, 17b1, i.e., to the cross members 13 fixed to each of the side members 12a, 12b, thereby reducing the risk of unintended deformation of the tray 3.

[0019] It is also conceivable to adopt a configuration for the cross member 13, similar to the battery pack tray described in Patent Document 1, which includes a lower cross member fixed to the bottom plate portion 11 and an upper cross member fixed to the lower cross member, extending above and parallel to the lower cross member with a gap between them. However, as described above, in the battery pack 1, if a single cross member 13 is provided at a position overlapping with the center position CP of the battery module 5 in the height direction with a gap between the underside 13a of the cross member 13 and the bottom plate portion 11, the risk of the cross member 13 bending due to the impact load of a side collision can be reduced. Therefore, compared to the configuration described in Patent Document 1, the number of cross members can be reduced, and as a result, the weight of the tray 31 can be reduced.

[0020] Furthermore, if the cross member 13 were fixed to the bottom plate 11 in a configuration in which the reinforcing frames 17a, 17b were provided, the above-described effects of the surfaces 17a1, 17b1 of the reinforcing frames 17a, 17b would be reduced, but in the battery pack 1, by providing a gap between the lower surface 13a of the cross member 13 and the bottom plate 11, the above-described effects of the surfaces 17a1, 17b1 can be reliably obtained. In addition to this configuration, by providing the cross member 13 so that the lower surface 13a of the cross member 13 is positioned higher in the height direction than each of the mounting frames 15a, 15b, the collision load in a side collision can be reliably transmitted to the cross member 13 by the surfaces 17a1, 17b1, thereby reducing the risk of unintended deformation of the tray 3.

[0021] In addition, in the battery pack 1, by leaving a gap between the upper surface 13b of the cross member 13 and the lid portion 4, the cable connected to the battery module 5 can be passed through the gap between the upper surface 13b and the lid portion 4, thereby making it possible to make the battery pack 1 more compact.

[0022] REFERENCE SIGNS LIST 1 Battery pack 3 Tray 4 Lid portion 5 Battery module (battery cell) 11 Bottom plate portion 12a Side member 12b Side member 13 Cross member 13a Lower surface (of cross member) 13b Upper surface (of cross member) 15a Mounting frame 15b Mounting frame 16 Fastening jig 17a Reinforcing frame 17a1 (surface of reinforcing frame) 17b Reinforcing frame 17b1 (surface of reinforcing frame)

Claims

1. A tray for a battery pack to be mounted on a vehicle, comprising: at least one battery cell; a bottom plate portion on which the at least one battery cell is placed; a pair of side members fixed to the bottom plate portion with a gap in the vehicle width direction, the pair of side members extending in the fore-and-aft direction of the vehicle; and at least one cross member extending in the vehicle width direction, wherein the at least one cross member overlaps with the center position of the at least one battery cell in the height direction, which is a direction perpendicular to the bottom plate portion, and is fixed to each of the pair of side members by being welded to each of the pair of side members.

2. A tray as described in claim 1, comprising: a pair of plate-shaped mounting frames fixed to each of the pair of side members so as to protrude in the vehicle width direction from the outer surfaces of each of the pair of side members, the mounting frames being engageable with fastening jigs for fixing the tray to the vehicle; and a reinforcing frame fixed to each of the pair of side members and each of the pair of mounting frames, wherein the reinforcing frame includes a surface that forms an acute angle with the bottom plate portion and faces outward in the vehicle width direction.

3. The tray according to claim 2, wherein a gap is provided between the bottom plate portion and the lower surface of the cross member that faces the bottom plate portion.

4. The tray according to claim 3, wherein the lower surface is positioned higher than the mounting frame in the height direction.

5. A battery pack comprising: a tray according to any one of claims 1 to 4; and a lid portion disposed above the tray in the height direction.

6. The battery pack according to claim 5, wherein a gap is provided between the lid and an upper surface of the cross member that faces the lid.

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