Fastening structure for strength members of battery cases

Abstract

To provide a fastening structure of a strength member used for a battery case for installing a battery module in a vehicle as a drive source to protect the battery module, which is highly effective in protecting the battery module against an external input load.SOLUTION: In a fastening structure of a strength member for fixing and holding a battery module in a battery case composed f a frame body, accommodating a battery module, and mounting it on a vehicle, the frame body has a rib extending inward from the bottom side of the inner wall, and the strength member includes a fastening portion having a pair of terminal parts on both left and right end sides, the terminal part being fastened to the rib, and a load input portion on the surface facing the inner wall.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fastening structure for a strength member used in a battery case that mounts a battery module as a driving source in a vehicle, and that protects the battery module. [Background technology]

[0002] 2. Description of the Related Art In electric vehicles, hybrid vehicles, and the like, a battery module made up of a secondary battery is mounted as a driving source, for example, under the floor of the vehicle. For example, Patent Document 1 discloses a battery pack in which a battery module is fixed to a bracket attached to a lower case. However, the bracket disclosed in the publication has a gap between it and the inner wall of the pack case, which makes it difficult for external input loads to be transmitted to the bracket, and there is a risk that the bracket will collapse in the forward / backward direction due to deformation of the inner wall of the pack case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6798310 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide a fastening structure for a strength member for a battery case that is used in a battery case for mounting a battery module in a vehicle as a power source, and that protects the battery module, and that has a high protective effect for the battery module against external input loads. [Means for solving the problem]

[0005] The fastening structure of the present invention is a fastening structure for a strength member for fixing and holding a battery module in a battery case that is constructed of a frame body and mounted on a vehicle, wherein the frame body has a rib extending from the lower side of the inner wall toward the inside, and the strength member has a pair of terminal parts at both end portions, and the terminal parts have a fastening portion that fastens to the rib and a load input portion on the surface facing the inner wall.

[0006] The battery case herein refers to a device that houses a so-called secondary battery that can be repeatedly charged and used, its control device, and the like, and is mounted, for example, under the floor of a vehicle. The battery case may have a frame body formed of, for example, front and rear frames and left and right frames, and a panel body attached to an opening of at least one of the frames. In the present invention, the left and right frames, which are susceptible to external impact, have ribs extending inward from the lower sides of their inner walls. By fastening the terminal parts that make up the strength members to these ribs, external loads input to the left and right frames are effectively transmitted to the strength members.

[0007] Here, if the terminal part and the rib are fastened to the lower side of the battery case, there is a risk that the strength member may tilt depending on how the input load is applied. Therefore, in the present invention, a load input portion that can easily absorb the load input is provided on the opposing surface of the terminal part that receives the load and comes into contact with the inner walls of the left and right frames. As a result, when the left and right frames receive an external impact, the load input portions of the terminal parts dig into the left and right frames, thereby preventing the strength members from collapsing or bending.

[0008] In the present invention, it is preferable that the load input portion has an uneven shape. In this way, the load input portion is likely to bite into the left and right frames.

[0009] In the present invention, the terminal part may be manufactured from an extruded material integrally formed with the load input portion. This makes it easy to provide a load input portion on the terminal part, which may be made of extruded aluminum, for example. [Effects of the Invention]

[0010] The present invention provides a fastening structure in which a load input portion is provided at the terminal part of a strength member that is fastened to a frame body that is susceptible to external impacts, and that receives a load and bites into the frame body, thereby suppressing collapse or bending deformation of the strength member. This improves the effect of protecting the battery module from external loads. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows an example of a fastening structure for a battery case strength member according to the present invention. [Figure 2] An example of connecting a strength member and a frame body is shown. [Figure 3] 10 shows an example of fixing a strength member to a battery module. [Figure 4] 10 shows an enlarged partial view of the strength member and the frame body when a load is applied. [Figure 5] Example 2 is shown below. DETAILED DESCRIPTION OF THE INVENTION

[0012] An example of a fastening structure for a battery case strength member according to the present invention will be described below with reference to the drawings. The reinforcing member 20 of the present invention is fastened to the inside of the battery case 10 which is mounted, for example, under the floor of the vehicle, to securely hold the battery module 100 . For convenience of explanation, the left and right directions are assumed to be directions susceptible to external impacts.

[0013] There are no restrictions on the material of the battery case 10. For example, as shown in FIG. 3, a frame body is formed by an aluminum left frame 11, a right frame 12, a front frame 13, and a rear frame 14, and a panel body 15 is attached to close the opening of the frame body. The left and right frames 11, 12 may have outer hollow portions 11d, 12d that protrude outward to absorb shocks applied from the outside. As shown in FIG. 1, the left and right frames 11, 12 have ribs 11b extending inward from the lower sides of their inner walls 11a, and the ribs 11b are provided with a plurality of fastening portions 11c at predetermined intervals. There are no limitations on the structure of the front and rear frames or panel body.

[0014] On the other hand, the strength member 20 has a protection part 24 extending in the left-right direction and a pair of terminal parts 21, 21 connected to the left and right end parts of the protection part 24, respectively. The terminal part 21 is connected by inserting the end of the protective part 24 into an approximately U-shaped insertion part that opens on the inside, but there is no limitation on the connection method, and it can be connected by, for example, friction stir welding or welding. The terminal part 21 is an extruded aluminum material having a hollow portion 21a, and has a fastening portion 22 inside the hollow portion 21a and a load input portion 21b with an uneven shape outside the hollow portion 21a. For example, as shown in FIG. 2, when the rib 11b (fastened portion 11c) of the left frame 11 and the fastening portion 22 of the terminal part 21 are fastened together using a bolt 23a and a nut 23b, the load input portion 21b faces the inner wall 11a. There are no limitations on the shape of the load receiving portion 21b as long as it comes into contact with the inner wall 11a of the left frame when it receives an external load and digs into the inner wall 11a. For example, the recesses and protrusions may be jagged with narrow intervals between them, or may be shaped such that the intervals between the recesses and protrusions vary as shown in FIG. The protective component 24 has a fixing portion 25 located inside the end portion that is inserted into the terminal component 21, and fixes and holds the battery module 100. As shown in FIG. 3, the protective component 24 may have a separate connecting component 28 in the middle or the like to fasten it to the panel body 15, thereby distributing the input load over the entire battery case. In this embodiment, the terminal part 21, the protective part 24, etc. are made of extruded aluminum, and the terminal part 21 is an example in which the load input portion 21b is integrally formed, but the present invention is not limited to this.

[0015] In the present invention, there is no limitation on the structure of the battery module. For example, as shown in FIG. 3, a battery module 100 has guard members 101, 101 provided at the ends of multiple battery cells, and by providing fixed portions on the guard members 101, they can be fixed to fixing portions 25 of the protective component 24 with bolts. For example, the guard members 101, 101 of two battery modules 100, 100 can be fixed alternately on the left and right sides from the front and rear direction to the two fixing portions 25, 25 on the left end side of one protective component 24, respectively.

[0016] FIG. 4 shows a plan view of the fastening state between the left frame and the strength member (terminal part 21) when an impact is applied to the left frame 11 from the outside on the left side. As shown in the figure, even if an external load is applied to the left frame 11 so as to bend it, the load input portion 21b of the strength member 20 (terminal part 21) bites into the left frame 11, preventing the strength member from collapsing or being bent. Furthermore, since the guard members 101, 101 are connected so as to straddle the strength members 20, 20 (protective components 24, 24) adjacent in the front-rear direction, it is possible to further prevent the strength members 20 from tipping over in the front-rear direction. [Explanation of symbols]

[0017] 11a Inner wall 11b Rib 20 Strength members 21 Terminal parts 21b Load input section 22 Fastening part

Claims

[Claim 1] A battery case is configured as a frame body and contains a battery module, and the battery case is mounted on a vehicle. The battery case includes a fastening structure for a strength member for fixing and holding the battery module, the fastening structure comprising: The frame has a rib extending inward from the lower side of the inner wall, The strength member has a pair of end pieces at both ends, the terminal part has a fastening portion fastened to the rib and a load input portion on a surface facing the inner wall, A fastening structure for a strength member for a battery case, wherein the load input portion has an uneven shape.