Vehicle mounting structure for battery pack and method for manufacturing same

Abstract

The invention relates to a vehicle-mounted structure of a battery pack and a method for manufacturing the same. Provided are a structure for mounting a battery pack on a vehicle and a method for manufacturing the same, which are capable of suppressing deterioration in the movement performance of the vehicle even when a common impact absorbing material is used. A vehicle mounting structure of a battery pack including a battery stack includes: a pair of impact absorbing materials extending in a vehicle front-rear direction so as to sandwich an outer side of the battery pack in a vehicle width direction, the impact absorbing materials being longer than the battery pack in the vehicle front-rear direction; and a crossing member extending in the vehicle width direction, both ends of the crossing member being respectively connected to the end portions of the impact absorbing materials.

Description

Technical Field

[0001] The present disclosure relates to a vehicle mounting structure for a battery pack to be mounted on a vehicle and a manufacturing method thereof. Background Art

[0002] A vehicle mounting structure for a battery pack is known that includes a pair of shock-absorbing materials extending in the vehicle front-rear direction so as to sandwich the outer side in the vehicle width direction of the battery pack (for example, refer to Japanese Unexamined Patent Application Publication No. 2023-046719). Summary of the Invention

[0003] However, shock-absorbing materials are mounted on the rocker of the vehicle body base on the side of the battery pack. Thus, there is a battery pack between the rockers, and the rigidity of the relative torsion of the rocker with respect to the rolling direction is increased. That is, the vehicle body and the battery pack are engaged with respect to the rolling direction and the rigidity is increased, so that the motion performance of the vehicle is improved.

[0004] On the other hand, for example, for battery packs with different battery capacities, a common shock-absorbing material is envisaged for cost reduction purposes. In this case, the length of the shock-absorbing material in the vehicle front-rear direction is determined to match the largest battery pack. Therefore, the shock-absorbing material may protrude in the vehicle front-rear direction beyond the battery pack. As a result, the rigidity of the relative torsion with respect to the rolling direction is reduced, and the motion performance of the vehicle may deteriorate.

[0005] The present disclosure has been completed to solve such problems, and a main object thereof is to provide a vehicle mounting structure for a battery pack and a manufacturing method thereof that can suppress deterioration of the motion performance of the vehicle even when a common shock-absorbing material is used.

[0006] One aspect of the present disclosure for achieving the above object is:

[0007] A vehicle mounting structure for a battery pack including a battery stack, comprising:

[0008] A pair of shock-absorbing materials extending in the vehicle front-rear direction so as to sandwich the outer side in the vehicle width direction of the battery pack and being longer than the battery pack in the vehicle front-rear direction; and

[0009] A cross member extending in the vehicle width direction, with both ends respectively connected to the end portions of the respective shock-absorbing materials.

[0010] In this one aspect,

[0011] The cross-sectional shape of both end portions of the cross member may be a U-shape opening outward in the vehicle width direction, and the end portions of the respective shock-absorbing materials may be respectively inserted into the openings of both end portions of the cross member.

[0012] In one mode,

[0013] The end portions of the impact absorbing materials and the both end portions of the cross member are connected by passing a connecting member having a length longer than the vertical direction length of the cross member by a predetermined value or more in the vertical direction.

[0014] One mode of the present disclosure for achieving the above object is:

[0015] A manufacturing method of a vehicle mounting structure of a battery pack including a battery stack, wherein,

[0016] A pair of impact absorbing materials longer than the battery pack in the vehicle front-rear direction are arranged in the vehicle front-rear direction so as to sandwich the outside in the vehicle width direction of the battery pack.

[0017] Both ends of a cross member extending in the vehicle width direction are respectively connected to the end portions of the respective impact absorbing materials.

[0018] According to the present disclosure, it is possible to provide a vehicle mounting structure of a battery pack and a manufacturing method thereof that can suppress deterioration of the vehicle's motion performance even when a common impact absorbing material is used.

[0019] The above and other objects, features, and advantages of the present disclosure will become more apparent from the detailed description and the drawings given herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a plan view of the vehicle mounting structure of the battery pack according to the present embodiment as viewed from above.

[0021] Figure 2 It is a view showing the state of the impact absorbing material and the battery pack at the time of a side collision of the vehicle.

[0022] Figure 3 It is along Figure 1 It is a sectional view taken along the line A-A shown and cutting the cross member in the vertical direction. DETAILED DESCRIPTION

[0023] Hereinafter, this embodiment will be described with reference to the drawings. Figure 1 It is a plan view of the vehicle mounting structure of the battery pack according to the present embodiment as viewed from above. The vehicle mounting structure 1 of the battery pack according to the present embodiment includes a battery pack 2, a pair of impact absorbing materials 3, and a cross member 4.

[0024] The battery pack 2 is mounted on a vehicle such as a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle, for example. The vehicle mounting structure 1 of the battery pack 2 is provided, for example, below the floor and inside the frame member of the vehicle.

[0025] The battery pack 2 houses, for example, a battery stack formed by laminating a plurality of battery cells inside a housing. The battery cells are composed of lithium-ion batteries or the like.

[0026] A pair of shock-absorbing materials (EA material: Energy Absorption) 3 are components for absorbing impacts from the side of the vehicle. The pair of shock-absorbing materials 3 are provided inside the rocker of the vehicle body base.

[0027] The pair of shock-absorbing materials 3 extend in the vehicle front-rear direction so as to sandwich the outer side in the vehicle width direction of the battery pack 2. Thus, for example, as Figure 2 shown, during a side collision of the vehicle or the like, it is also possible to suitably protect the side of the battery pack 2, particularly the part without a battery frame or a vehicle body frame.

[0028] The pair of shock-absorbing materials 3 are longer than the battery pack 2 in the vehicle front-rear direction. This is conceived to use a common shock-absorbing material 3 for battery packs 2 with different battery capacities for the purpose of cost reduction and improved mounting expandability. In this case, the length of the shock-absorbing material 3 in the vehicle front-rear direction is determined in accordance with the largest battery pack 2. Therefore, as described above, the shock-absorbing material 3 is longer than the battery pack 2 in the vehicle front-rear direction, and it may be in a state where the shock-absorbing material 3 protrudes from the battery pack 2 in the vehicle front-rear direction.

[0029] However, as described above, in the case where the shock-absorbing material protrudes from the battery pack in the vehicle front-rear direction, the rigidity against relative torsion in the rolling direction of the vehicle decreases, and the motion performance of the vehicle may deteriorate.

[0030] In contrast, the vehicle mounting structure 1 of the battery pack 2 according to the present embodiment is as Figure 1 shown, and includes a cross member 4 that extends in the vehicle width direction and whose both ends are respectively connected to the end portions of the respective shock-absorbing materials 3. Through this cross member 4, the rigidity against relative torsion in the rolling direction of the vehicle is increased, and deterioration of the motion performance of the vehicle can be suppressed.

[0031] Figure 3 is a cross-sectional view when the cross member 4 is cut in the vertical direction along the Figure 1 line A-A shown. The cross member 4 is composed of, for example, a metal member having a sectional second moment that can withstand a side impact load of 300 kN. The cross member 4 is composed of, for example, a 1180 material (high-tensile steel plate) of iron with a plate thickness of 2 mm or more. Thus, the relative torsion in the rolling direction of the vehicle can be withstood.

[0032] The cross member 4 is composed of a hollow support member 41 extending in the vehicle width direction and a pair of patch members 42 respectively connected to both ends of the support member 41. Both ends of the support member 41 and the pair of patch members 42 are connected by welding or the like, but are not limited thereto. The support member 41 and the pair of patch members 42 may also be integrally formed.

[0033] The cross-section of the support member 41 is formed in a square shape. The cross-sectional shape of the patch member 42 at both ends of the support member 41 is formed in a U shape opening to the outside in the vehicle width direction as Figure 3 shown. The rear end portions of the respective shock absorbing materials 3 are respectively inserted into the openings of the patch members 42. Thereby, the manufacturing tolerance in the vehicle width direction of the cross member 4 can be absorbed.

[0034] For example, the bolt 5 penetrates vertically through the rear end portions of the respective shock absorbing materials 3 and the patch members 42 of the cross member 4. By fastening the nut 7 to the penetrated bolt 5 with the washer 6 interposed therebetween, the rear end portions of the respective shock absorbing materials 3 and the patch members 42 of the cross member 4 are connected by the bolt 5 and the nut as connecting members.

[0035] Here, for example, it is assumed that the shock absorbing material 3 is made of aluminum, and the housing of the battery pack 2 and the cross member 4 are made of iron. In this case, due to the difference in the linear expansion coefficients of the shock absorbing material 3 and the housing of the battery pack 2 and the cross member 4, displacement occurs between the two members, so it is necessary to absorb this displacement.

[0036] For example, when the bolts are arranged in the horizontal direction, a displacement of about 1 mm due to the above-mentioned linear expansion coefficient occurs in a length of 1 m in the horizontal direction. Therefore, a structure for absorbing the displacement due to the linear expansion coefficient is required.

[0037] In contrast, in the present embodiment, the length of the bolt 5 is longer than the vertical length of the cross member 4 by a predetermined value or more. Thereby, while deforming the bolt 5, the displacement due to the linear expansion coefficient can be absorbed by the length of the bolt 5 that is more than the predetermined value. The predetermined value is, for example, about 1 to 2 mm, which is a length capable of absorbing the above-mentioned displacement.

[0038] Next, the vehicle mounting structure 1 of the battery pack 2 and its manufacturing method will be described. First, a pair of shock absorbing materials 3 that are longer than the battery pack 2 in the vehicle front-rear direction are arranged in the vehicle front-rear direction so as to sandwich the outside in the vehicle width direction of the battery pack 2. Both ends of the cross member 4 extending in the vehicle width direction are respectively connected to the rear end portions of the respective shock absorbing materials 3. In addition, the battery pack 2 may be arranged between the pair of shock absorbing materials 3 after connecting the cross member 4 and the respective shock absorbing materials 3.

[0039] Although several embodiments of the present disclosure have been described, these embodiments are merely illustrative and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention and are included in the invention described in the claims and the scope of equivalents thereof.

[0040] From the disclosure thus described, it will be apparent that the embodiments of the present disclosure can vary in many ways. Such variations should not be regarded as a departure from the spirit and scope of the present disclosure, and all such modifications that are obvious to those skilled in the art are intended to be included within the scope of the appended claims.

Claims

1. A vehicle-mounted structure of a battery pack including a battery stack, wherein: have: a pair of impact absorbing materials extending in the front-rear direction of the vehicle so as to sandwich the outer side of the battery pack in the vehicle width direction and being longer than the battery pack in the front-rear direction of the vehicle; as well as The cross member extends in the vehicle width direction, and both ends are connected to the ends of the impact absorbing materials, respectively.

2. The vehicle mounting structure of the battery pack according to claim 1, wherein: The cross-sectional shape of both end portions of the cross member is a U-shape that opens outward in the vehicle width direction, and the end portions of each of the impact absorbing materials are respectively fitted into the openings of both end portions of the cross member.

3. The vehicle mounting structure of the battery pack according to claim 2, wherein: The end portions of each of the impact absorbing materials and both end portions of the intersection member are connected by allowing a connection member longer than the vertical length of the intersection member by a predetermined value or more to penetrate in the vertical direction.

4. A method for manufacturing a vehicle-mounted structure of a battery pack including a battery stack, wherein: A pair of impact absorbing materials longer than the battery pack in the vehicle front-rear direction are arranged in the vehicle front-rear direction so as to sandwich the outer side of the battery pack in the vehicle width direction, Both ends of a cross member extending in the vehicle width direction are connected to end portions of each of the impact absorbing materials.

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