Vehicle undercarriage

Abstract

The objective is to obtain a vehicle understructure that can ensure an allowable amount of intrusion from a collision component entering from the outside in the vehicle width direction, and can suppress deformation of the battery case. [Solution] The vehicle understructure 10 comprises a battery case 20 housing a battery module 26, a reinforcing member 30 provided so as to sandwich the outer wall portion 22B of the battery case 20 in the vehicle width direction from the inside and outside, and a support bracket 36 that supports the battery case 20 by having one end attached to a portion of the reinforcing member 30 provided on the outside of the battery case 20 and the other end attached to a support portion 18 of the vehicle body, wherein the support bracket 36 has lower bending rigidity than the reinforcing member 30.

Description

TECHNICAL FIELD

[0001] The present invention relates to a vehicle lower structure.

BACKGROUND ART

[0002] A vehicle lower structure in which the other end of a bracket, one end of which is connected to a battery unit (battery case) arranged on the lower side of a floor panel, is connected to a rocker via a side frame, has been conventionally known (see, for example, Patent Document 1).

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0003]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

PROBLEM TO BE SOLVED BY THE INVENTION

[0004] However, in the configuration as described above, since the distance between the rocker and the bracket is short, the allowable entry amount for a collision member that has entered from the vehicle width direction outer side is small. In addition, since no reinforcing member or the like is provided for the battery case, among the load input to the bracket from the vehicle width direction outer side, the load whose energy is not absorbed by the deformation of the bracket is transmitted to the battery case, which may cause the battery case to deform.

[0005] Accordingly, an object of the present invention is to obtain a vehicle lower structure that can secure an allowable entry amount for a collision member that has entered from the vehicle width direction outer side, and can suppress deformation of a battery case.

MEANS FOR SOLVING THE PROBLEM

[0006] To achieve the above objective, the vehicle understructure of the first embodiment of the present invention comprises a battery case housing a battery module, a reinforcing member provided so as to sandwich the outer wall portion of the battery case in the vehicle width direction from the inside and the outside, and a support bracket that supports the battery case by having one end attached to a portion of the reinforcing member provided on the outside of the battery case and the other end attached to a support portion of the vehicle body, wherein the bending rigidity of the support bracket is lower than that of the reinforcing member.

[0007] According to the first embodiment of the invention, a reinforcing member is provided so as to sandwich the outer wall portion in the vehicle width direction of the battery case housing the battery module from the inside and the outside. The battery case is supported by one end of a support bracket being attached to a portion of the reinforcing member provided on the outside of the battery case, and the other end of the support bracket being attached to a support portion of the vehicle body.

[0008] Here, the support bracket has lower bending rigidity than the reinforcing member. Therefore, when an impact member entering from the outside in the vehicle width direction collides with the support bracket, the support bracket deforms by bending in the opposite direction to the entry side, moving the battery case in the opposite direction to the entry side. This ensures a permissible amount of entry for the impact member entering from the outside in the vehicle width direction, and the impact is mitigated and absorbed, thus suppressing deformation of the battery case.

[0009] Furthermore, the vehicle understructure of the second embodiment of the present invention is the vehicle understructure of the first embodiment, wherein, in a cross-sectional view taken from the front-rear direction of the vehicle, the reinforcing member has a substantially rectangular closed cross-sectional shape that sandwiches the outer wall portion of the battery case in the vehicle width direction.

[0010] According to the second embodiment of the invention, in a cross-sectional view taken from the front-rear direction of the vehicle, the reinforcing member has a substantially rectangular closed cross-sectional shape that sandwiches the outer wall portion of the battery case in the vehicle width direction. Therefore, the rigidity of the reinforcing member is ensured, and the battery case is effectively moved to the side opposite to the entry side.

[0011] Furthermore, a third embodiment of the vehicle understructure according to the present invention is a vehicle understructure according to the first or second embodiment, wherein the support portion is located inward in the vehicle width direction from the rocker, and the support bracket has a vertical wall portion whose direction is normal to the vehicle width direction.

[0012] According to the third embodiment of the invention, the support portion is located inward in the vehicle width direction from the rocker, and the support bracket has a vertical wall portion whose normal direction is the vehicle width direction. In other words, a space is secured on the outside of the vertical wall portion in the vehicle width direction. Therefore, even if an impact member entering from the outside in the vehicle width direction collides with the vertical wall portion of the support bracket, the outward bending deformation in the vehicle width direction of the vertical wall portion of the support bracket on the opposite side of that support bracket is not hindered, and the battery case is effectively moved to the side opposite to the entry side. [Effects of the Invention]

[0013] As described above, according to the present invention, it is possible to ensure an allowable amount of intrusion for a collision member entering from the outside in the vehicle width direction, and to suppress deformation of the battery case. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic rear view showing the vehicle understructure according to this embodiment. [Figure 2] This is a schematic rear view showing the state in which the forks of a forklift collide with the undercarriage of the vehicle according to this embodiment. [Modes for carrying out the invention]

[0015] The embodiments of the present invention will be described in detail below with reference to the drawings. For the sake of explanation, in each figure, the arrow UP will indicate the upward direction of the vehicle, the arrow FR will indicate the forward direction of the vehicle, and the arrow RH will indicate the rightward direction of the vehicle. In the following description, unless otherwise specified, the directions of up, down, front, back, and left and right will refer to the up, down, front, back, and left and right directions of the vehicle. The left and right direction is synonymous with the vehicle width direction.

[0016] As shown in Figure 1, the vehicle understructure 10 according to this embodiment includes a battery case 20 mounted below the floor panel 16 of the vehicle 12. A pair of left and right rockers 14 are provided at the outer end of the vehicle 12 in the width direction. The rocker 14 has an inner panel 14A and an outer panel 14B that are roughly hat-shaped when viewed in cross-section from the front and rear directions (hereinafter simply referred to as "cross-sectional view"). The upper and lower flange portions of the inner panel 14A and the upper and lower flange portions of the outer panel 14B are joined to each other, resulting in a roughly rectangular closed cross-sectional shape.

[0017] The outer ends of the floor panel 16 in the vehicle width direction are joined to the inner panels 14A of the rockers 14, and the floor panel 16 is supported by the left and right rockers 14. When viewed from the front or rear direction (hereinafter referred to as "rear view"), the lower end of the battery case 20 (the bottom wall 22A of the lower case 22, which will be described later) is located below the lower end 14C of the rocker 14 (the lower end of the lower flange), and this vehicle 12 has a low minimum ground clearance.

[0018] Furthermore, an under member 18, which serves as a support portion extending in the longitudinal direction, is attached to the underside of a predetermined portion of the floor panel 16 located inward in the vehicle width direction from the rocker 14. The under member 18 is formed in a roughly hat shape with the upper side open in cross-section, and a flange portion 18A that extends integrally from its upper end outward and inward in the vehicle width direction is attached to the underside of the floor panel 16 by joining it.

[0019] The battery case 20 has a lower case 22 and an upper case 24. The lower case 22 has a bottom wall 22A, a peripheral wall 22B which is integrally erected on the periphery of the bottom wall 22A, and a flange portion 22C which extends outward in the vehicle width direction from the upper end of the peripheral wall 22B. The upper case 24 has a top wall 24A, a peripheral wall 24B which is integrally suspended on the periphery of the top wall 24A, and a flange portion 24C which extends outward in the vehicle width direction from the lower end of the peripheral wall 24B.

[0020] The battery case 20 is configured such that the flange portion 24C of the upper case 24 and the flange portion 22C of the lower case 22 are vertically overlapped and joined together. The battery case 20 accommodates a battery module 26 therein. The battery module 26 is configured by stacking a plurality of battery cells 28 in the vehicle width direction.

[0021] Further, end plates 27 having a predetermined thickness are disposed on the outer sides of the plurality of battery cells 28 in the vehicle width direction. The plurality of battery cells 28 are restrained in the vehicle width direction by the left and right end plates 27. The end plate 27 only needs to be a highly rigid plate, and may be made of metal or resin.

[0022] Reinforcement members 30 extending in the front-rear direction are provided on both sides of the lower case 22 of the battery case 20 in the vehicle width direction. The reinforcement member 30 is provided so as to sandwich the peripheral wall 22B of the lower case 22 from the inner side (the inside of the battery case 20) and the outer side (the outside of the battery case 20). Specifically, the reinforcement member 30 is composed of an inner reinforce 32 provided on the inner side of the lower case 22, and an outer reinforce 34 provided on the outer side of the lower case 22.

[0023] When viewed from the rear, the inner reinforce 32 has a flat top wall 32A whose normal direction is the vertical direction, a flat side wall 32B (with the normal direction being the vehicle width direction) integrally suspended from the inner end portion of the top wall 32A in the vehicle width direction, an upper flange portion 32C integrally erected from the outer end portion of the top wall 32A in the vehicle width direction, and a lower flange portion 32D integrally protruding inward in the vehicle width direction from the lower end portion of the side wall 32B.

[0024] The outer reinforcement 34, when viewed from the rear, has a flat top wall 34A with the vertical direction as the normal direction, a flat side wall 34B integrally suspended from the outer end of the top wall 34A in the vehicle width direction (with the vehicle width direction as the normal direction), an upper flange portion 34C integrally erected from the inner end of the top wall 34A in the vehicle width direction, and a flat bottom wall 34D integrally projecting inward in the vehicle width direction from the lower end of the side wall 34B (with the vertical direction as the normal direction).

[0025] The top wall 32A of the inner reinforcement 32 and the top wall 34A of the outer reinforcement 34 are positioned at the same height, and the upper flange portion 32C of the inner reinforcement 32 is joined to the inner surface of the periphery wall 22B, and the upper flange portion 34C of the outer reinforcement 34 is joined to the outer surface of the periphery wall 22B, so as to sandwich the periphery wall 22B of the lower case 22 between the upper flange portion 32C of the inner reinforcement 32 and the upper flange portion 34C of the outer reinforcement 34.

[0026] Furthermore, the lower flange portion 32D of the inner reinforcement 32 is joined to the inner surface of the bottom wall 22A, and the inner end portion 34E in the vehicle width direction of the bottom wall 34D of the outer reinforcement 34 is joined to the outer surface of the bottom wall 22A, so that the bottom wall 22A of the lower case 22 is sandwiched between the lower flange portion 32D of the inner reinforcement 32 and the inner end portion 34E in the vehicle width direction of the bottom wall 34D of the outer reinforcement 34. As a result, in cross-sectional view, the reinforcing member 30 has a substantially rectangular closed cross-sectional shape, sandwiching the peripheral wall 22B of the lower case 22 of the battery case 20.

[0027] Furthermore, a flat module bracket 25, with its vertical direction as the normal, is provided on the outer side of the battery module 26 in the vehicle width direction. This module bracket 25 is superimposed on the top wall 32A of the inner reinforcement 32 from above and joined to it. Therefore, the inner reinforcement 32 can also be said to be a support reinforcement that supports the battery module 26 via the module bracket 25. The outer reinforcement 34 can also be said to be an outer reinforcing reinforcement that reinforces the outer side of the battery case 20 (lower case 22) in the vehicle width direction.

[0028] Furthermore, the outer reinforcement 34 of the reinforcing member 30 is connected to the floor panel 16 by a plurality of support brackets 36 provided at predetermined intervals in the front-rear direction. Each support bracket 36 has a flat vertical wall portion 36A with the vehicle width direction as its normal direction when viewed from the rear, and the lower end (one end) of the vertical wall portion 36A is a lower flange portion 36B that extends integrally inward in the vehicle width direction.

[0029] The lower flange portion 36B is superimposed from below onto the bottom wall 34D of the outer reinforcement 34 of the reinforcing member 30 and fastened and secured by bolts 38. The lower part of the vertical wall portion 36A is also superimposed from the outside onto the side wall 34B of the outer reinforcement 34 of the reinforcing member 30 and fastened and secured by bolts 38.

[0030] Furthermore, the upper end (other end) of the vertical wall portion 36A of each support bracket 36 is an upper flange portion 36C that extends outward in the vehicle width direction as a single unit. This upper flange portion 36C is superimposed on the lower wall 18B of the under member 18 from below and fastened and fixed by bolts 38. As a result, the battery case 20 is supported by the under member 18 (vehicle body) via the support bracket 36 and the reinforcing member 30 (outer reinforcement 34).

[0031] Furthermore, the support bracket 36 is configured to have lower bending rigidity than the reinforcing members 30 (inner reinforcement 32 and outer reinforcement 34). In other words, the support bracket 36 (vertical wall portion 36A) is configured to be more susceptible to deflection deformation, at least in the vehicle width direction, compared to the reinforcing members 30, through the selection of materials and reduction of thickness.

[0032] The operation of the vehicle understructure 10 according to this embodiment, which has the configuration described above, will now be explained.

[0033] As described above, the inner reinforcement 32 and outer reinforcement 34 of the reinforcing member 30 are provided so as to sandwich the peripheral wall 22B of the lower case 22 of the battery case 20 housing the battery module 26 from the inside and outside. The battery case 20 is supported by the lower flange portion 36B of the support bracket 36 being attached to the outer reinforcement 34 of the reinforcing member 30, and the upper flange portion 36C of the support bracket 36 being attached to the under member 18 which is joined to the floor panel 16.

[0034] Here, the under member 18 is located inward in the vehicle width direction compared to the rocker 14, and the support bracket 36 has a vertical wall portion 36A whose normal direction is the vehicle width direction. In other words, a predetermined space is secured on the outside of the vertical wall portion 36A in the vehicle width direction. Furthermore, the support bracket 36 (vertical wall portion 36A) has lower bending rigidity than the reinforcing member 30.

[0035] Therefore, as shown in Figure 2, even if the forks 40 of a forklift (not shown), which is an example of a collision member entering from the outside in the vehicle width direction, collide with the vertical wall portion 36A of the support bracket 36, the vertical wall portion 36A of each support bracket 36 can bend and deform toward the opposite side from the entry side, allowing the battery case 20 to move like a swing toward the opposite side (outward in the vehicle width direction) (see the white arrows shown in Figure 2).

[0036] In other words, when the claw portion 40 entering from the outside in the vehicle width direction collides with the vertical wall portion 36A of the support bracket 36, the vertical wall portion 36A of the support bracket 36 on the entry side deforms inward in the vehicle width direction. The vertical wall portion 36A of the support bracket 36 on the opposite side of the entry side deforms outward in the vehicle width direction without being hindered from deforming outward. As a result, the battery case 20 can be moved to the opposite side (outward in the vehicle width direction) from the entry side.

[0037] Thus, according to the vehicle understructure 10 of this embodiment, the battery case 20 can be effectively moved to the opposite side from the entry side (outward in the vehicle width direction), and the impact from the claw portion 40 can be mitigated and absorbed. In other words, according to this embodiment, the allowable amount of entry of the claw portion 40 that enters from the outside in the vehicle width direction can be secured by the bending deformation of the left and right support brackets 36, and deformation of the battery case 20 can be suppressed or prevented.

[0038] Furthermore, in cross-sectional view, the reinforcing member 30 has a roughly rectangular closed cross-sectional shape that sandwiches the peripheral wall 22B of the lower case 22 of the battery case 20. Therefore, the rigidity of the reinforcing member 30 can be ensured (making it difficult for the reinforcing member 30 to deform), and the battery case 20 can be moved more effectively toward the opposite side from the entry side (outward in the vehicle width direction). As a result, deformation of the battery case 20 can be more effectively suppressed or prevented.

[0039] The vehicle understructure 10 according to this embodiment has been described above based on the drawings. However, the vehicle understructure 10 according to this embodiment is not limited to the illustrated version, and can be modified as appropriate without departing from the spirit of the present invention. For example, the collision member is not limited to the forklift tines 40, but also includes members that may enter during a side collision of the vehicle 12. [Explanation of Symbols]

[0040] 10. Vehicle understructure 14 Rocka 18 Undermember (support part) 20 Battery Cases 22B Peripheral wall (wall) 26 Battery Modules 30 Reinforcement members 36 Support bracket 36A Vertical wall section

Claims

1. A battery case containing a battery module, A reinforcing member is provided so as to sandwich the outer wall portion of the battery case in the vehicle width direction from the inside and the outside, A support bracket that supports the battery case, with one end attached to a portion of the reinforcing member located on the outside of the battery case and the other end attached to a support portion of the vehicle body, Equipped with, The support bracket is a vehicle understructure having lower bending rigidity than the reinforcing member.

2. In a cross-sectional view of the vehicle from the front or rear, The vehicle understructure according to claim 1, wherein the reinforcing member has a substantially rectangular closed cross-sectional shape that sandwiches the outer wall portion of the battery case in the vehicle width direction.

3. The vehicle understructure according to claim 1 or claim 2, wherein the support portion is located inward in the vehicle width direction from the rocker, and the support bracket has a vertical wall portion whose direction is normal to the vehicle width direction.

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