Fastening structure and battery pack

Abstract

To facilitate fastening of fastening structures and objects to be fastened. [Solution] The fastening structure 300 comprises a bracket assembly 310 and a welding bolt 320. The welding bolt 320 has a head 322 welded to the bracket assembly 310 and a shaft portion 324 that protrudes from the head 322 through the bracket assembly 310. The bracket assembly 310 has a thick portion 310a that at least partially overlaps the head 322 and a thin portion 310b that at least partially occupies the periphery of the thick portion 310a. The thickness of the thick portion 310a is greater than the thickness of the thin portion 310b.

Description

Technical Field

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[0001] The present invention relates to a fastening structure and a battery pack.

Background Art

[0002] In recent years, various fastening structures for fastening fastened objects such as electronic components have been developed. The fastening structure may include a base material such as a bracket and a fastener such as a welding bolt. The fastener may have a welded portion welded to the base material as exemplified by the head of the welding bolt and a protruding portion protruding through the base material from the welded portion as exemplified by the shaft portion of the welding bolt.

[0003] Patent Document 1 describes stud welding. In this stud welding, a first base material and a second base material are laminated on each other, and a pin is stud welded to the first base material.

[0004] Patent Document 2 describes a welding technique. In this welding technique, an aluminum sheet is added between the welded product and the welding head.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0007] One example of the object of the present invention is to facilitate fastening of fastening structures and fastened objects. Other objects of the present invention will become apparent from the description herein. [Means for solving the problem]

[0008] One aspect of the present invention is as follows: 1. Substrate and A fastener having a welded portion welded to the base material and a protruding portion that extends through the base material from the welded portion, Equipped with, The base material has a first portion that at least partially overlaps the welded portion, and a second portion that at least partially occupies the periphery of the first portion. A fastening structure in which the thickness of the first portion is greater than the thickness of the second portion. 2. The fastening structure according to 1, wherein the first portion of the base material includes a plurality of laminates stacked in a direction substantially parallel to the thickness of the first portion. 3. The fastening structure according to 2., wherein the plurality of laminates are welded to each other after the welded portion is welded to some of the laminates. 4. A battery pack comprising the fastening structure described in any one of items 1 to 3. [Effects of the Invention]

[0009] According to the above-described embodiment of the present invention, fastening of fastening structures and objects to be fastened can be facilitated. [Brief explanation of the drawing]

[0010] [Figure 1] This is a top view of the battery pack according to the embodiment. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This is a top view of a welding bolt according to an embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0012] Figure 1 is a top view of a battery pack 10 according to an embodiment.

[0013] For illustrative purposes, Figure 1 shows the X, Y, and Z axes, respectively. In Figure 1, the white circle with a black dot indicating the Z axis indicates that the Z-axis arrow is pointing towards the viewer. Hereafter, unless otherwise specified, the Z direction is the vertical direction, the X direction is one of the horizontal directions perpendicular to the vertical direction, and the Y direction is another horizontal direction perpendicular to both the vertical and X directions. Hereafter, unless otherwise specified, the direction in which the Z-axis arrow is pointed is assumed to be the upper side of the vertical direction. However, the relationships between the X, Y, Z directions, vertical direction, and horizontal direction are not limited to those described herein.

[0014] Unless otherwise specified, the +X side refers to the side to which the X-axis arrow is pointed, and the -X side refers to the opposite side from which the X-axis arrow is pointed. Unless otherwise specified, the +Y side refers to the side to which the Y-axis arrow is pointed, and the -Y side refers to the opposite side from which the Y-axis arrow is pointed. Unless otherwise specified, the +Z side refers to the side to which the Z-axis arrow is pointed, and the -Z side refers to the opposite side from which the Z-axis arrow is pointed.

[0015] The battery pack 10 according to this embodiment comprises a plurality of battery modules 100, a housing 200, a fastening structure 300, and electronic components 400.

[0016] In the example shown in FIG. 1, four battery modules 100 are arranged in two rows and two columns in the Y direction and the X direction, respectively. The number and arrangement of the battery modules 100 are not limited to the example shown in FIG. 1. The battery pack 10 may have, for example, only one battery module 100. Each battery module 100 has a plurality of battery cells (not shown) that are electrically connected to each other, for example, in series, in parallel, or in a combination of series and parallel.

[0017] The housing 200 houses a plurality of battery modules 100, a fastening structure 300, and electronic components 400. In FIG. 1, the housing 200 is shown in a state where an upgrade covering the upper part of the +Z side of the plurality of battery modules 100 is omitted.

[0018] The fastening structure 300 is located on the +Z side with respect to at least some of the battery modules 100. In the example shown in FIG. 1, the fastening structure 300至少部分地与在 -X 侧布置的两个电池模块 100 在 Z 方向上重叠。紧固结构体 300 相对于多个电池模块 100 的位置不限于图 1 所示的示例。

[0019] The electronic component 400 is located on the +Z side with respect to the fastening structure 300. As will be described later using FIGS. 2 and 3, the electronic component 400 is fastened by the fastening structure 300.

[0020] FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. FIG. 3 is a top view of the welding bolt 320 according to the embodiment. In FIG. 2, the white circle with a black dot indicating the X-axis indicates that the arrow of the X-axis is directed toward the front of the paper surface. The A-A line in FIG. 1 passes through the center of the welding bolt 320 shown in FIG. 3.

[0021] As shown in FIG. 2, the fastening structure 300 has a bracket assembly 310 and a welding bolt 320. The electronic component 400 serves as a fastened object fastened to the fastening structure 300. The electronic component 400 is, for example, a printed circuit board (PCB). The fastened object fastened to the fastening structure 300 is not limited to the electronic component 400.

[0022] The bracket assembly 310 serves as a base for positioning the electronic component 400 substantially perpendicular to the Z-direction. The bracket assembly 310 includes a bracket 312 and a spacer 314.

[0023] The bracket 312 is made of a conductor such as metal. The bracket 312 has a roughly plate-like shape and is positioned approximately perpendicular to the Z direction. The electronic component 400 is mounted on the upper surface of the bracket 312 on the +Z side. The bracket 312 has a thickness that is approximately parallel to the Z direction. In the example shown in Figure 2, the thickness of the bracket 312 in the Z direction is approximately constant regardless of the position of the bracket 312.

[0024] The spacer 314 is made of a conductor such as metal. The spacer 314 has a roughly plate-like shape and is positioned roughly perpendicular to the Z direction. The spacer 314 has a thickness that is roughly parallel to the Z direction. In the example shown in Figure 2, the thickness of the spacer 314 in the Z direction is roughly constant regardless of the position of the spacer 314.

[0025] As shown in Figure 2, the bracket 312 and spacer 314 overlap each other in the Z direction, with the spacer 314 positioned on the -Z side relative to the bracket 312. In the example shown in Figure 2, the bracket 312 and spacer 314 are joined to each other via a joint 316 formed across both the bracket 312 and spacer 314 in the Z direction. In this embodiment, the joint 316 is formed by spot welding. As shown in Figure 2, the joint 316 is provided in a region of the bracket assembly 310 that does not overlap with the electronic component 400 in the Z direction. Therefore, even if a weld mark caused by the joint 316 is formed on the +Z side surface of the bracket 312, interference between the weld mark and the electronic component 400 can be suppressed, making it easier to position the electronic component 400 substantially perpendicular to the Z direction. In one example, the area of ​​the spacer 314 perpendicular to the Z direction may be larger than the area of ​​the electronic component 400 perpendicular to the Z direction, so that the joint 316 is provided in a region of the bracket assembly 310 that does not overlap with the electronic component 400 in the Z direction.

[0026] The method of joining the bracket 312 and the spacer 314 is not limited to a method using the joint portion 316. For example, the bracket 312 and the spacer 314 may be joined to each other via an adhesive provided between the -Z side surface of the bracket 312 and the +Z side surface of the spacer 314.

[0027] The area of ​​the spacer 314 perpendicular to the Z direction is less than the area of ​​the bracket 312 perpendicular to the Z direction. Therefore, as shown in Figure 2, the bracket assembly 310 has a thickened portion 310a where the bracket 312 and spacer 314 overlap each other in the Z direction, and a thinned portion 310b located at least partially around the thickened portion 310a in the Z direction. The thickness of the thickened portion 310a in the Z direction is greater than the thickness of the thinned portion 310b in the Z direction by the thickness of the spacer 314 in the Z direction.

[0028] The welding bolt 320 is a fastener for fastening the bracket assembly 310 and the electronic component 400 together. The welding bolt 320 includes a head 322 and a shaft 324.

[0029] As shown in Figure 3, the head 322 is approximately circular when viewed from the Z direction. As shown in Figure 3, a plurality of protrusions 323 are provided around the shaft portion 324 on the +Z side of the head 322. The shape of the head 322 and the number and arrangement of the protrusions 323 are not limited to the example shown in Figure 3. The head 322 is a welded portion welded to the -Z side of the spacer 314 by the melting of the plurality of protrusions 323.

[0030] As shown in Figure 2, the shaft portion 324 is a projection that extends from the +Z side surface of the head portion 322, passing through the spacer 314 and the bracket 312 toward the +Z side. The upper end of the shaft portion 324 on the +Z side protrudes upward toward the +Z side from the upper surface of the bracket 312 on the +Z side. In the example shown in Figure 2, the portion of the shaft portion 324 that protrudes from the upper surface of the bracket 312 on the +Z side passes through the electronic component 400. This portion of the shaft portion 324 and the electronic component 400 are fastened to each other, for example, by screws.

[0031] If the head 322 were directly welded to the -Z side surface of the bracket 312 without the spacer 314, welding marks caused by the welding of the projection 323 may be formed on the portion of the bracket 312 located around the shaft portion 324 on the +Z side surface. Hereinafter, where necessary, "without spacer 314" means that the head 322 is directly welded to the -Z side surface of the bracket 312 without the spacer 314. In the absence of spacer 314, welding marks caused by the welding of the projection 323 may make it difficult to ensure the flatness of the portion of the bracket 312 located around the shaft portion 324 on the +Z side surface. Therefore, in the absence of spacer 314, it may be difficult to position the electronic component 400 approximately perpendicular to the Z direction on the portion of the bracket 312 located around the shaft portion 324 on the +Z side surface. However, in this embodiment, as shown in Figure 2, the thick portion 310a of the bracket assembly 310, including the bracket 312 and spacer 314, overlaps with the head 322 at least partially in the Z direction. Therefore, compared to the case without the spacer 314, welding marks caused by welding of the projection 323 are less likely to form on the portion of the bracket 312 located around the shaft portion 324 on the +Z side face, making it easier to ensure the flatness of the portion of the bracket 312 located around the shaft portion 324 on the +Z side face. Consequently, compared to the case without the spacer 314, it becomes easier to position the electronic component 400 substantially perpendicular to the Z direction, and the fastening structure 300 and the electronic component 400 can be easily fastened.

[0032] In one embodiment, the bracket assembly 310 has two laminates stacked in the Z direction, including a bracket 312 and a spacer 314. Therefore, the thick portion 310a and the thin portion 310b can be formed more easily than by molding the base material corresponding to the bracket assembly 310 so that multiple portions having different thicknesses corresponding to the thick portion 310a and the thin portion 310b are formed. However, the base material corresponding to the bracket assembly 310 may be molded so that multiple portions having different thicknesses corresponding to the thick portion 310a and the thin portion 310b are formed. The number of laminates included in the bracket assembly 310 may be three or more, not just two, such as the bracket 312 and the spacer 314.

[0033] In the example shown in Figure 2, the area of ​​the spacer 314 perpendicular to the Z direction is larger than the area of ​​the electronic component 400 perpendicular to the Z direction. Therefore, the joint 316 can be formed around the electronic component 400 in the Z direction. In the example shown in Figure 2, the area of ​​the spacer 314 perpendicular to the Z direction is smaller than the area of ​​the bracket 312 perpendicular to the Z direction. Therefore, the thickness in the Z direction of the part that should function as the thickened portion 310a of the bracket assembly 310 can be partially increased. Therefore, the weight and cost of the bracket assembly 310 can be reduced compared to the case where the overall thickness in the Z direction of the bracket assembly 310 is increased.

[0034] In this embodiment, the spacer 314 is positioned on the -Z side relative to the bracket 312, and the electronic component 400 is mounted on the +Z side upper surface of the bracket 312. However, the electronic component 400 may be mounted on the +Z side upper surface of the spacer 314 even when the spacer 314 is positioned on the +Z side relative to the bracket 312. When the spacer 314 is positioned on the +Z side relative to the bracket 312, the head 322 is welded to the -Z side surface of the bracket 312. Even when the spacer 314 is positioned on the +Z side relative to the bracket 312, welding marks caused by the welding of the projection 323 are less likely to form around the shaft portion 324 on the +Z side surface of the spacer 314, making it easier to fasten the fastening structure 300 and the electronic component 400.

[0035] Next, an example of a manufacturing method for the fastening structure 300 will be described.

[0036] First, with the head 322 positioned on the -Z side relative to the spacer 314 and the shaft portion 324 penetrating the spacer 314, the multiple protrusions 323 are melted to weld the spacer 314 and the head 322 together. As shown in Figure 2, welding of the spacer 314 and the head 322 may form weld marks 315 on the +Z side of the spacer 314 around the shaft portion 324, caused by the welding of the protrusions 323. Note that the weld marks 315 do not appear directly in the cross-section shown in Figure 2; therefore, in Figure 2, the weld marks 315 appearing on a plane parallel to the cross-section shown in Figure 2 are depicted with dashed lines.

[0037] Next, with the spacer 314 positioned on the -Z side relative to the bracket 312 and the shaft portion 324 passing through the bracket 312, a joint portion 316 is formed by spot welding, and the bracket 312 and the spacer 314 are welded to each other.

[0038] In the method described above, the bracket 312 and the spacer 314 are welded to each other after the spacer 314 and the head 322 are welded to each other. Therefore, compared to the case where the spacer 314 and the head 322 are welded to each other after the bracket 312 and the spacer 314 are welded to each other, the weld marks 315 can be more easily concealed by the bracket 312, and it can be more easily ensured that there are no weld marks on the +Z side face of the bracket 312 caused by the welding of the projection 323. If the bracket assembly 310 has three or more stacks stacked in the Z direction, the multiple stacks may be welded to each other after the head 322 and at least one stack excluding the stack on the +Z side on which the electronic component 400 is directly mounted are welded to each other. However, in a method different from the method described above, the spacer 314 and the head 322 may be welded to each other after the bracket 312 and the spacer 314 are welded to each other.

[0039] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted. [Explanation of Symbols]

[0040] 10 Battery pack, 100 Battery module, 200 Housing, 300 Fastening structure, 400 Electronic component, 310 Bracket assembly, 310a Thick section, 310b Thin section, 312 Bracket, 314 Spacer, 315 Weld mark, 316 Joint, 320 Weld bolt, 322 Head, 323 Projection, 324 Shaft

Claims

1. Substrate and A fastener having a welded portion welded to the base material and a protruding portion that extends through the base material from the welded portion, Equipped with, The base material has a first portion that at least partially overlaps the welded portion, and a second portion that at least partially occupies the periphery of the first portion. A fastening structure in which the thickness of the first portion is greater than the thickness of the second portion.

2. The fastening structure according to claim 1, wherein the first portion of the base material includes a plurality of laminates stacked in a direction substantially parallel to the thickness of the first portion.

3. The fastening structure according to claim 2, wherein the plurality of laminates are welded to one another after the welded portion is welded to some of the laminates.

4. A battery pack comprising the fastening structure described in any one of claims 1 to 3.

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