Battery housing structure

Abstract

A battery housing structure S includes a housing 10 for a battery 2 that is disposed on a vehicle body floor 1, the housing 10 covering the periphery of the battery 2. The housing 10 includes: a side wall 11 that extends in a vehicle front-back direction and that has a closed cross section; and a front wall 12 and a back wall 13 that extend in a vehicle width direction. End portions in the vehicle width direction of at least one of the front wall 12 and the back wall 13 each have a first rib 21 that extends in the vehicle front-back direction, and a second rib 23 that extends in the vehicle front-back direction, inward of the first rib 21 in the vehicle width direction. The first rib 21 is in close proximity to or in contact with a first wall 11A from the inside in the vehicle width direction, the first wall 11A forming the closed cross section of the side wall 11. The second rib 23 is in close proximity to or in contact with a second wall 11B from the inside in the vehicle width direction, the second wall 11B being located inward of the first wall 11A in the vehicle width direction and forming the closed cross section of the side wall.

Description

Battery housing structure

[0001] The present invention relates to a battery housing structure.

[0002] Patent Document 1 discloses a battery case that is composed of a cast member arranged at the front end of the vehicle, a rear wall at the rear of the vehicle, side walls arranged on both the left and right sides along the vehicle width direction, and a bottom wall that connects the lower ends of the cast member, the rear wall, and the pair of left and right side walls.

[0003] Japanese Patent Application Laid-Open No. 2021-59142

[0004] However, in Patent Document 1, the side walls have relatively lower rigidity than the cast members at the front of the vehicle, so when a load is input to the vehicle body from the outside in the vehicle width direction, the side walls may deform and damage the battery.

[0005] An object of the present invention is to provide a battery housing structure that can suppress damage to the battery when a load is input to the vehicle body from the outside in the vehicle width direction.

[0006] A battery housing structure according to one aspect of the present invention includes a battery housing that surrounds a battery arranged on a vehicle floor. The housing has side walls that have a closed cross section extending in the vehicle longitudinal direction, and front and rear walls that extend in the vehicle width direction. At least one of the front and rear walls has a first rib extending in the vehicle longitudinal direction at its end in the vehicle width direction and a second rib extending in the vehicle longitudinal direction and located inward of the first rib in the vehicle width direction. The first rib is adjacent to or abuts, from the inside in the vehicle width direction, the first wall that forms the closed cross section of the side wall. The second rib is adjacent to or abuts, from the inside in the vehicle width direction, the second wall that is located inward of the first wall and forms the closed cross section of the side wall.

[0007] According to a battery housing structure according to one aspect of the present invention, damage to the battery can be suppressed when a load is input to the vehicle body from the outside in the vehicle width direction.

[0008] Fig. 1 is a plan view showing a battery housing structure according to an embodiment. Fig. 2A is a perspective view showing the structure of a front wall and a side wall according to an embodiment. Fig. 2B is a perspective view showing a joining structure between the front wall and the side wall according to an embodiment. Fig. 2C is a cross-sectional view of the joining structure between the front wall and the side wall according to an embodiment. Fig. 3A is a perspective view showing the structure of a rear wall and a side wall according to an embodiment. Fig. 3B is a perspective view showing the joining structure between the rear wall and the side wall according to an embodiment. Fig. 4 is a perspective view showing a fastening structure between a battery housing structure according to an embodiment and a floor panel.

[0009] A battery housing structure S mounted on a vehicle according to an embodiment will be described below with reference to the drawings. In each drawing, FW and BW indicate the front and rear in the vehicle longitudinal direction, respectively, UP and DN indicate the upper and lower in the vehicle vertical direction, and LH and RH indicate the left and right in the vehicle width direction, respectively. In the following description, the front, front side, rear, and rear side in the vehicle longitudinal direction, the upper, upper side, lower, and lower in the vehicle vertical direction, and the left, left side, right, and right in the vehicle width direction will be simply referred to as the front, front side, rear, rear side, upper, upper side, lower, lower, left, left side, right, and right, respectively. Furthermore, components having the same functions as those already described will be designated by the same reference numerals, and their description will be omitted.

[0010] The battery housing structure S includes a housing 10 for the battery 2 that surrounds the battery 2 disposed on the vehicle floor 1 (see FIGS. 1 and 4). The battery 2 is disposed under a floor panel (hereinafter referred to as the floor panel 1) that constitutes the vehicle floor 1. The vehicle floor is, for example, the components that constitute the floor of the vehicle body (floor panel, cross member, floor tunnel, etc.).

[0011] The housing 10 protects the battery 2 from loads applied from outside the vehicle. The housing 10 has left and right side walls 11, 11, a front wall 12 located at the front, and a rear wall 13 located at the rear (see FIG. 1). A cover 14 is attached to the bottom of the housing 10 (see FIG. 4).

[0012] Each of the side walls 11, 11 is a cylindrical member that extends in the vehicle longitudinal direction and has a closed cross section R. Each of the side walls 11, 11 has a first wall 11A that is arranged on the outer side in the vehicle width direction and parallel to the vehicle vertical direction, and a second wall 11B that is arranged on the inner side in the vehicle width direction than the first wall 11A and parallel to the vehicle vertical direction.

[0013] The closed cross section R may be a combination of multiple rectangular closed cross sections, as illustrated in Figures 2A and 3A. In this embodiment, the closed cross section R of the side wall 11 disposed on the left side in the vehicle width direction has a generally L-shaped outer shape in rear view (see Figure 2C). That is, each side wall 11 includes a first wall 11A and a second wall 11B parallel to the vehicle vertical direction, a lateral wall 11C parallel to the vehicle width direction, an upper wall 11D parallel to the vehicle vertical direction, and a top wall 11E and a bottom wall 11F parallel to the vehicle width direction. The upper wall 11D is located between the first wall 11A and the second wall 11B in the vehicle width direction, is arranged parallel to the vehicle vertical direction, and is located above the second wall 11B. The lateral wall 11C is located between the upper end of the second wall 11B and the lower end of the upper wall 11D, and is arranged parallel to the vehicle width direction. The top wall 11E is provided between the upper end of the first wall 11A and the upper end of the top wall 11D, and is arranged parallel to the vehicle width direction. The bottom wall 11F is provided between the lower end of the first wall 11A and the lower end of the second wall 11B, and is arranged parallel to the vehicle width direction (see Figures 2A to 2C). The configuration of the closed cross section R is not limited to the above, and for example, the outer shape of the closed cross section R may be rectangular. The configuration of the second wall 11B is not limited to the above, and may be composed of multiple walls, or may have a wall inclined with respect to the vehicle up-down direction. In addition, the top wall 11D may be defined as the second wall. The side walls 11, 11 are made of, for example, extruded material formed by extrusion molding.

[0014] The front wall 12 extends in the vehicle width direction, and both ends are formed in a generally rectangular shape (see FIG. 2A). The front ends of the side walls 11, 11 are joined to the rear ends of both ends of the front wall 12 in the vehicle width direction (see FIG. 2B). The rear wall 13 has a generally rectangular cross section and extends in the vehicle width direction (see FIG. 3A). The rear ends of the side walls 11, 11 are joined to the front ends of both ends of the rear wall 13 in the vehicle width direction (see FIG. 3B).

[0015] The front wall 12 and the rear wall 13 may be made of cast metal. That is, the front wall 12 and the rear wall 13 may be formed by melting a cast metal material and injecting it into a mold to perform casting. Casting allows for the formation of reinforcing structures such as ribs, protrusions, and locally thickened structures. Therefore, the rigidity of the front wall 12 and the rear wall 13 can be improved relatively easily compared to when the front wall 12 and the rear wall 13 are formed by methods other than casting. The front wall 12 and the rear wall 13 according to the embodiment have reinforcing structures such as multiple vertical ribs extending in the up-down direction and multiple horizontal ribs extending in the vehicle width direction. Therefore, when a load is input in the fore-and-aft direction of the vehicle, the front wall 12 and the rear wall 13, which are made of highly rigid cast metal, can absorb the impact. Furthermore, the load can be distributed to the side walls 11, 11 joined to the front wall 12 and the rear wall 13, thereby absorbing the energy of the collision.

[0016] The front wall 12 and the rear wall 13 may be connected by a connecting member 31 (see FIG. 1 ). In the battery housing structure S according to the embodiment, one end of the connecting member 31 is fixed to a central portion 12A at the rear end of the front wall 12. The other end of the connecting member 31 is fixed to a central portion 13A at the front end of the rear wall 13. The connecting member 31 is formed of a member that is continuously connected in the longitudinal direction of the vehicle. The connecting member 31 is made of, for example, an extruded material formed by extrusion molding. Note that a plurality of connecting members 31 may be arranged side by side in the vehicle width direction. Furthermore, the fixing points of the connecting member 31 to the front wall 12 and the rear wall 13 are not limited to those described above.

[0017] An outer rib (hereinafter referred to as the outer rib 21) serving as a first rib 21 and an inner rib (hereinafter referred to as the inner rib 23) serving as a second rib 23 are provided at the rear ends of both ends of the front wall 12 in the vehicle width direction (see FIG. 2A ). In the following explanation, the structures of the outer rib 21 and the inner rib 23 and the joining structure between the front wall 12 and the side wall 11 will be described using a structure arranged on the left side in the vehicle width direction as an example. The structure arranged on the right side in the vehicle width direction is similar, so its explanation will be omitted. In the embodiment, the structures of the outer rib 21 and the inner rib 23 and the joining structure between the front wall 12 and the side wall 11 are arranged on the left and right sides in the vehicle width direction, respectively, but they may be arranged on only one of the left and right sides.

[0018] The outer rib 21 is formed to extend rearward from the rear end of the left end of the front wall 12. The outer rib 21 has a first lateral rib 22A provided at an upper portion, a second lateral rib 22B provided at a lower portion, and a first longitudinal rib 22C provided between the first lateral rib 22A and the second lateral rib 22B (see FIG. 2A ). The first lateral rib 22A extends along the vehicle width direction and curves downward at its left end to extend along the vehicle up-down direction, forming the first longitudinal rib 22C. The first longitudinal rib 22C curves inward at its lower end in the vehicle width direction and extends along the vehicle width direction, forming the second lateral rib 22B.

[0019] The inner rib 23 is formed inward in the vehicle width direction from the rear end of the left end of the front wall 12 and extends rearward. The inner rib 23 has a second longitudinal rib 24A provided at its upper portion, a third longitudinal rib 24B provided at its lower portion, and a third lateral rib 24C provided between the second longitudinal rib 24A and the third longitudinal rib 24B (see FIG. 2A ). The second longitudinal rib 24A extends along the vehicle vertical direction and curves inward in the vehicle width direction at its lower end to extend along the vehicle width direction, forming the third lateral rib 24C. The third lateral rib 24C curves downward at its right end to extend along the vehicle vertical direction, forming the third longitudinal rib 24B. The third lateral rib 24C of the inner rib 23 is located between the first lateral rib 22A and the second lateral rib 22B of the outer rib 21 in the vehicle vertical direction.

[0020] The front end of the side wall 11 is joined to the rear end of the left end of the front wall 12. In the joined state, the first wall 11A forming the closed cross section R of the side wall 11 is positioned outward in the vehicle width direction from the outer rib 21 (see FIGS. 2B and 2C). That is, the outer rib 21 is adjacent to the inner surface of the first wall 11A from the inner side in the vehicle width direction. Also, in the joined state, the second wall 11B forming the closed cross section R of the side wall 11 is positioned outward in the vehicle width direction from the inner rib 23 (see FIGS. 2B and 2C). That is, the inner rib 23 is adjacent to the outer surface of the second wall 11B from the inner side in the vehicle width direction.

[0021] In this embodiment, the front end of the side wall 11 is welded to the rear end of the left end of the front wall 12. The outer rib 21 may abut the inner surface of the first wall 11A from the inside in the vehicle width direction, or may be welded to it. Similarly, the inner rib 23 may abut the outer surface of the second wall 11B from the inside in the vehicle width direction, or may be welded to it. The inner rib 23 is adjacent to or abuts the outer surface of the top wall 11D from the inside in the vehicle width direction (including when welded to it). The inner rib 23 is adjacent to or abuts the outer surface of the lateral wall 11C from above in the vehicle vertical direction. The outer rib 21 is adjacent to or abuts the outer surface of the top wall 11E from above in the vehicle vertical direction (including when welded to it). The outer rib 21 is adjacent to or abuts the outer surface of the bottom wall 11F from below in the vehicle vertical direction (including when welded to it).

[0022] With the above-described joining structure, when a load is input in the vehicle width direction and the first wall 11A of the side wall 11 deforms inward in the vehicle width direction, the first wall 11A is supported from the inside in the vehicle width direction by the outer rib 21 adjacent to the first wall 11A. This suppresses inward deformation of the first wall 11A in the vehicle width direction. Similarly, when the second wall 11B of the side wall 11 deforms inward in the vehicle width direction, the second wall 11B is supported from the inside in the vehicle width direction by the inner rib 23 adjacent to the second wall 11B. This suppresses inward deformation of the second wall 11B in the vehicle width direction. Therefore, the rigidity of the side wall 11 in the vehicle width direction can be improved compared to a configuration that does not have the outer rib 21 and the inner rib 23. The shapes and positions of the outer rib 21 and the inner rib 23 are not limited to those described above, and they can be configured in any shape and position as long as the inner rib 23 is positioned more inward in the vehicle width direction than the outer rib 21, the outer rib 21 is close to or abuts the first wall 11A from the inside in the vehicle width direction, and the inner rib 23 is close to or abuts the second wall 11B from the inside in the vehicle width direction.

[0023] An outer rib 25 and an inner rib 27 are provided at the rear ends of both ends in the vehicle width direction of the rear wall 13, respectively (see FIG. 3A). In the following explanation, the configuration of the outer rib 25 and the inner rib 27 and the joining structure between the rear wall 13 and the side wall 11 will be described using a structure arranged on the left side in the vehicle width direction as an example. The structure arranged on the right side in the vehicle width direction is similar, so explanation will be omitted. In the embodiment, the structure of the outer rib 25 and the inner rib 27 and the joining structure between the rear wall 13 and the side wall 11 are arranged on the left and right sides in the vehicle width direction, but they may be arranged on only one of the left and right sides.

[0024] The outer rib 25 extends forward from the front end of the left end of the rear wall 13. The outer rib 25 has a first horizontal rib 26A provided at its upper portion, a second horizontal rib 26B provided at its lower portion, and a first vertical rib 26C provided between the first horizontal rib 26A and the second horizontal rib 26B (see FIG. 3A ). These configurations are similar to those of the outer rib 21 on the front wall 12, and therefore, a description thereof will be omitted. The inner rib 27 is provided inward in the vehicle width direction from the outer rib 25 and extends forward from the front end of the left end of the rear wall 13. The inner rib 27 has a second vertical rib 28A provided at its upper portion, a third vertical rib 28B provided at its lower portion, and a third horizontal rib 28C provided between the second vertical rib 28A and the third vertical rib 28B. These configurations are similar to those of the inner rib 23 on the front wall 12, and therefore, a description thereof will be omitted.

[0025] The rear end of the side wall 11 is joined to the front end of the left end of the rear wall 13. In the joined state, the first wall 11A forming the closed cross section R of the side wall 11 is positioned outward in the vehicle width direction from the outer rib 25 (see FIG. 3B). That is, the outer rib 25 is adjacent to the inner surface of the first wall 11A from the inner side in the vehicle width direction. Also, in the joined state, the second wall 11B forming the closed cross section R of the side wall 11 is positioned outward in the vehicle width direction from the inner rib 27 (see FIG. 3B). That is, the inner rib 27 is adjacent to the outer surface of the second wall 11B from the inner side in the vehicle width direction. In the embodiment, the rear end of the side wall 11 is joined to the front end of the left end of the rear wall 13 by welding. The outer rib 25 may abut the inner surface of the first wall 11A from the inner side in the vehicle width direction, or may be joined by welding. Similarly, the inner rib 27 may abut the outer surface of the second wall 11B from the inner side in the vehicle width direction, or may be joined by welding. The shapes and positions of the outer rib 25 and the inner rib 27 are not limited to those described above and may be different from those of the outer rib 21 and the inner rib 23. The shapes and positions of the outer rib 25 and the inner rib 27 may be configured to have any shape and position as long as the inner rib 27 is located more inward in the vehicle width direction than the outer rib 25, the outer rib 25 is close to or abuts the first wall 11A from the inside in the vehicle width direction (including when joined by welding), and the inner rib 27 is close to or abuts the second wall 11B from the inside in the vehicle width direction (including when joined by welding).

[0026] The front wall 12 may have a pair of left and right fastening portions 41A, 41B protruding forward from the front end. In the battery housing structure S according to the embodiment, of the fastening portions 41A1, 41A2 constituting the pair of left fastening portions 41A, the fastening portion 41A1 located on the outer side in the vehicle width direction is fixed to a side member 4, which is a skeletal structure of the vehicle (see FIG. 4 ). Of the fastening portions 41A1, 41A2, the fastening portion 41A2 located on the inner side in the vehicle width direction is fixed to the floor panel 1 via a connecting part (see FIG. 4 ). Of the fastening portions 41B1, 41B2 constituting the pair of right fastening portions 41B, the fastening portion 41B1 located on the outer side in the vehicle width direction is fixed to the side member 4, which is a skeletal structure of the vehicle. Of the fastening portions 41B1, 41B2, the fastening portion 41B2 located on the inner side in the vehicle width direction is fixed to the floor panel 1 via a connecting part.

[0027] Each of the fastening portions 41A1, 41A2, 41B1, and 41B2 has a substantially semicircular shape, with an attachment hole near the center of each end. The fastening portions 41A1, 41A2, 41B1, and 41B2 are thick-walled, and the battery 2 is fastened to the vehicle body via the attachment hole. Although not shown, the upper surface of the front wall 12 is formed with a female thread for fastening the upper case of the battery 2 with a bolt. The female thread portion is thicker in the fore-and-aft direction of the vehicle than the other portions, eliminating the need for fasteners such as pop nuts. This prevents steps or gaps from occurring between the upper surface of the front wall 12 and the upper case. This, for example, reduces the need for watertight seals or other components between the upper surface of the front wall 12 and the upper case, simplifying the structure.

[0028] (1) The battery housing structure S includes a housing 10 for a battery 2 that surrounds a battery 2 disposed on a vehicle floor 1. The housing 10 includes a side wall 11 that extends in the vehicle longitudinal direction and has a closed cross section R, and a front wall 12 and a rear wall 13 that extend in the vehicle width direction. The vehicle width ends of at least one of the front wall 12 and the rear wall 13 include outer ribs 21, 25, which are first ribs extending in the vehicle longitudinal direction, and inner ribs 23, 27, which are second ribs extending in the vehicle longitudinal direction and located inward of the outer ribs 21, 25 in the vehicle width direction. The outer ribs 21, 25 are adjacent to or abut, from the inside in the vehicle width direction, a first wall 11A that forms the closed cross section of the side wall 11. The inner ribs 23, 27 are adjacent to or abut, from the inside in the vehicle width direction, a second wall 11B that is located inward of the first wall 11A in the vehicle width direction and forms the closed cross section R of the side wall 11.

[0029] With the above configuration, when a load is input in the vehicle width direction, the outer ribs 21, 25 and the inner ribs 23, 27 can suppress deformation of the first wall 11A and the second wall 11B, thereby suppressing deformation of the side wall 11 and improving rigidity in the vehicle width direction.

[0030] (2) In the embodiment, the outer ribs 21, 25 and the inner ribs 23, 27 each have a transverse rib 22A, 22B, 24C, 26A, 26B, 28C extending in the vehicle width direction. This provides a structure that is strong against a load input in the vehicle width direction. This further improves the rigidity in the vehicle width direction.

[0031] (3) Furthermore, in this embodiment, the lateral ribs are formed as first lateral ribs 22A, 26A and second lateral ribs 22B, 26B, which are provided at both ends of the outer ribs 21, 25 in the vehicle vertical direction. This allows the lateral ribs 22A, 22B, 26A, 26B, which have high strength against loads input in the vehicle width direction, to be provided on the top and bottom. This further improves rigidity in the vehicle width direction. Furthermore, the first lateral ribs 22A, 26A and the second lateral ribs 22B, 26B are respectively adjacent to or abutting (including being joined by welding) the inner wall or outer wall of the side wall 11. This allows them to be used for positioning the side wall during the manufacturing process.

[0032] (4) In the embodiment, the inner ribs 23, 27 are disposed between the first lateral ribs 22A, 26A and the second lateral ribs 22B, 26B in the vehicle up-down direction and include the third lateral ribs 24C, 28C extending in the vehicle width direction. This provides a structure that is strong against loads input in the vehicle width direction in the portion between the first lateral ribs 22A, 26A and the second lateral ribs 22B, 26B in the vehicle up-down direction. This further improves the rigidity in the vehicle width direction.

[0033] (5) Furthermore, in the embodiment, the connecting member 31 formed of a continuous member connects the central portions of the front wall 12 and the rear wall 13. This makes it possible to suppress deformation of the central portions of the front wall 12 and the rear wall 13 when a load is input in the vehicle longitudinal direction. As a result, it is possible to improve rigidity in the vehicle longitudinal direction.

[0034] The above-described embodiments are merely examples described to facilitate understanding of the invention. The technical scope of the invention is not limited to the specific technical matters disclosed in the above-described embodiments, but also includes various modifications, changes, alternative technologies, etc. that can be easily derived therefrom.

[0035] DESCRIPTION OF SYMBOLS 1 Floor panel (vehicle body floor) 2 Battery 10 Housing 11 Side wall 11A First wall 11B Second wall 12 Front wall 13 Rear wall 21, 25 Outer rib (first rib) 22A, 26A First horizontal rib (horizontal rib) 22B, 26B Second horizontal rib (horizontal rib) 23, 27 Inner rib (second rib) 24C, 28C Third horizontal rib 31 Connecting member R Closed cross section S Battery housing structure

Claims

1. A battery housing structure comprising: a battery housing covering the periphery of a battery arranged on a vehicle floor, the housing having: a side wall having a closed cross-section extending in a fore-and-aft direction of the vehicle; and a front wall and a rear wall extending in a vehicle width direction, the vehicle width direction ends of at least one of the front wall and rear wall each have a first rib extending in the fore-and-aft direction of the vehicle and a second rib extending in the fore-and-aft direction of the vehicle on the inner side of the first rib in the vehicle width direction, the first rib being in close proximity to or in contact with a first wall forming the closed cross-section of the side wall from the inner side in the vehicle width direction, and the second rib being in close proximity to or in contact with a second wall located inward in the vehicle width direction from the first wall and forming the closed cross-section of the side wall, from the inner side in the vehicle width direction.

2. The battery housing structure according to claim 1, wherein the first rib and the second rib each have a lateral rib extending in the vehicle width direction.

3. A battery housing structure as set forth in claim 2, wherein the lateral rib forms a first lateral rib and a second lateral rib provided at both ends of the first rib in the vehicle vertical direction.

4. A battery housing structure as described in claim 3, wherein the second rib is disposed between the first lateral rib and the second lateral rib in the vehicle vertical direction and has a third lateral rib extending in the vehicle width direction.

5. A battery housing structure according to any one of claims 1 to 4, further comprising a connecting member formed of a continuous member that connects central portions of the front wall and rear wall together.