Battery pack mounting structure

Abstract

To provide a battery pack mounting structure that is advantageous in terms of increasing durability of the battery pack mounting structure.SOLUTION: At a location of a side frame 12 where a battery cross member 20 is attached, a support member 26 is provided which is joined to the side frame 12 and has a support plate part 2602 which faces an underside of the side frame 12 at a predetermined distance in a vertical direction of the vehicle. An end part 20A of the battery cross member 20 in an extension direction is clamped and attached between the underside of the side frame 12 and the support plate part 2602.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a mounting structure for a battery pack. [Background technology]

[0002] Patent document 1 proposes a battery pack mounting structure for attaching a battery pack to the underside of a vehicle body, in which multiple battery cross-members extending in the vehicle width direction are provided at intervals in the fore-and-aft direction of the vehicle on the underside of the battery pack, and both ends of the battery cross-members in the vehicle width direction are attached to a pair of side frames via bolts and nuts. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-12524 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional structure shown in Patent Document 1, when the bolts deteriorate and break due to the effects of vibrations applied during driving, the strength of the attachment of the battery pack to the side frame decreases, which is disadvantageous in terms of improving the durability of the battery pack attachment structure. The present invention has been made in view of the above circumstances, and has as its object to provide a battery pack mounting structure that is advantageous in terms of increasing the durability of the battery pack mounting structure. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, one embodiment of the present invention is a battery pack mounting structure in which a plurality of battery cross-members extending in the vehicle width direction at intervals in the fore-and-aft direction of the vehicle are provided on the underside of a battery pack mounted on a vehicle, and both ends of the extending direction of the plurality of battery cross-members are attached to a pair of side frames, and a support member is provided that is joined to the side frames and has a support plate portion that faces the underside of the side frames at a predetermined interval in the vertical direction of the vehicle, and the ends of the extending direction of the battery cross-members are attached by being clamped between the underside of the side frames and the support plate portion. In addition, one embodiment of the present invention is characterized in that a bush is attached to the end of the battery cross member in the extension direction, and is inserted between the underside of the side frame and the support plate portion, and the bush has an outer tube connected to the end of the battery cross member in the extension direction, an inner tube arranged radially inside the outer tube, and an elastic body provided between the outer tube and the inner tube, and the bush is clamped between the underside of the side frame and the support plate portion by clamping the inner tube with a bolt inserted through the support plate, the inner tube, and the underside of the side frame. In addition, one embodiment of the present invention is characterized in that the support member includes a vertical plate portion extending upward from the support plate portion and joined to the outer surface of the side frame facing outward in the vehicle width direction, and an upper plate portion extending inward in the vehicle width direction from the upper end of the vertical plate portion and joined to the upper surface of the side frame. In one embodiment of the present invention, a plurality of the support members are provided in accordance with the plurality of battery cross members. In addition, one embodiment of the present invention is characterized in that the length of the support member in the fore-and-aft direction of the vehicle is greater than the distance between the battery cross member located furthest forward of the vehicle and the battery cross member located furthest rearward of the vehicle among the multiple battery cross members, and a space portion open to the inside in the vehicle width direction is provided between the underside of the side frame and the support plate portion, into which the end of the battery cross member can be inserted, and the support plate portion is provided with a plurality of openings formed in an open manner to the inside in the vehicle width direction, so that the end of the battery cross member can be inserted into the space portion from below, in accordance with the spacing between the multiple battery cross members. [Effects of the Invention]

[0006] According to one embodiment of the present invention, the end of the battery cross member in the extension direction is clamped and attached between the underside of the side frame and the support plate portion, which is advantageous in increasing the rigidity of the attachment point of the battery cross member to the side frame and in increasing the durability of the battery pack attachment structure. Furthermore, if a bushing is attached to the end of the battery cross member in the extension direction and the bushing is clamped between the underside of the side frame and the support plate by clamping the inner tube with a bolt inserted through the support plate, the inner tube, and the underside of the side frame, the bushing can absorb vibrations and twisting of the vehicle body and prevent these vibrations and twisting from being transmitted to the battery pack, which is advantageous for protecting the battery pack.Furthermore, the bushing can absorb vibrations and twisting of the battery pack and prevent these vibrations and twisting from being transmitted to the vehicle body, which is advantageous for improving ride comfort and quietness. Furthermore, if the support member has a vertical plate portion and an upper plate portion, this is more advantageous in improving the attachment strength of the support member to the side frame, and is more advantageous in increasing the durability of the battery pack attachment structure. Furthermore, by providing multiple support members to match multiple battery cross members, the size of each support member can be minimized to a level sufficient to support the battery cross members, which is advantageous in reducing the weight of the support members. Furthermore, if the support member is formed so that its length in the fore-and-aft direction of the vehicle is greater than the distance between the battery cross-member located furthest forward of the vehicle and the battery cross-member located furthest rearward of the vehicle among the multiple battery cross-members, and a space portion open to the inside in the vehicle width direction is provided between the underside of the side frame and the support plate portion, into which the end of the battery cross-member can be inserted, and the support plate portion has multiple openings formed in an open shape to the inside in the vehicle width direction, so that the end of the battery cross-member can be inserted into the space portion from below, in accordance with the spacing between the multiple battery cross-members, this will be more advantageous in increasing the strength and rigidity of the support member, even more advantageous in increasing the durability of the battery pack mounting structure, and will also be advantageous in accommodating larger and heavier battery packs. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a bottom view showing the mounting structure of the battery pack according to the first embodiment. [Figure 2] 1 is a perspective view of the battery pack mounting structure from which the battery pack has been removed, viewed obliquely from above. FIG. [Figure 3] FIG. 2 is a perspective view of a battery cross member. [Figure 4] FIG. 2 is a perspective view of a cross section taken along line AA in FIG. 1, with the battery case omitted. [Figure 5] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 6] FIG. 10 is a bottom view showing the mounting structure of the battery pack according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle body structure according to an embodiment of the present invention will now be described with reference to the drawings. In the following drawings, the symbol FR indicates the front of the vehicle, the symbol UP indicates the upper side of the vehicle, and the symbol HL indicates the width direction of the vehicle. Furthermore, in this embodiment, the vehicle is described as an electric vehicle that is driven solely by a motor, but the present invention is widely applicable to vehicles that use a motor as a drive source, such as hybrid vehicles or plug-in hybrid vehicles (PHEVs) that can be externally charged or externally powered, and that are equipped with a battery pack that supplies power to the motor.

[0009] As shown in FIG. 1, a pair of metal side frames 12 extending in the fore-and-aft direction of the vehicle are provided at the bottom of the vehicle 10 and spaced apart in the vehicle width direction, and the battery pack 14 is disposed between the pair of side frames 12 below the passenger compartment or the luggage compartment. The battery pack 14 includes a battery case 14A, a battery pack (not shown) housed in the battery case 14A, and an electrical component that controls the battery pack. In this embodiment, the battery case 14A has a substantially rectangular shape in plan view with long sides extending in the front-rear direction of the vehicle.

[0010] A metal battery frame 16 that supports the battery pack 14 is provided on a bottom surface 1402 of the battery case 14A. As shown in Figures 1, 2, and 3, the battery frame 16 includes a pair of battery side members 18 extending in the fore-and-aft direction of the vehicle on both widthwise sides of the bottom surface 1402 of the battery case 14A, and a plurality of battery cross members 20 extending in the vehicle width direction at locations spaced apart in the fore-and-aft direction of the vehicle and connecting the pair of battery side members 18. In this embodiment, three battery cross members 20 are provided, and connecting members 22 are provided at both ends of each battery cross member 20, and the end portions 20A of the battery cross members 20 are connected to the battery side members 18 via the connecting members 22, and therefore the battery cross members 20 are configured to include the connecting members 22. The battery side member 18 may be omitted, in which case the connecting member 22 is also omitted. As shown in Figures 3 and 5, the cross section of the battery cross member 20 is formed into a rectangular frame shape that is elongated in the fore-and-aft direction of the vehicle, consisting of an upper wall 2002, a bottom wall 2004, a front wall 2006, and a rear wall 2008, and has a closed cross section structure.

[0011] As shown in FIGS. 4 and 5, weld nuts 24 are provided on the lower surface of the upper wall 2002 of each battery cross member 20 near both ends in the vehicle width direction. Then, with the bottom surface 1402 of the battery case 14A placed on the upper wall 2002 of each battery cross member 20, the battery pack 14 is attached to the battery cross member 20 by fastening a bolt B1 through a frame-shaped frame 1410 provided inside the battery case 14A to each weld nut 24.

[0012] As shown in FIG. 5, the cross section of the side frame 12 is formed into a vertically elongated rectangular frame shape consisting of an upper wall 1202, a bottom wall 1204, an inner side wall 1206, and an outer side wall 1208, and has a closed cross section structure. Support members 26 are provided at the locations of the side frames 12 where the battery cross members 20 are attached, and in this embodiment, a total of six support members 26 are provided. In other words, multiple support members 26 are provided to match the multiple battery cross members 20. The support member 26 is made of metal, and as shown in Figures 4 and 5, it includes a support plate portion 2602 that faces the underside of the bottom wall 1204 of the side frame 12 at a predetermined distance in the vertical direction of the vehicle, a vertical plate portion 2604 that extends upward from the support plate portion 2602 and is joined to the side of the outer side wall 1208 of the side frame 12 that faces outward in the vehicle width direction and forms a substantially L-shape with the support plate portion 2602, and an upper plate portion 2606 that extends from the upper end of the vertical plate portion 2604 along the side frame 12 and extends to the inside in the vehicle width direction and is joined to the upper surface of the upper wall 1202 of the side frame 12. The support plate portion 2602 is provided with a bolt insertion hole 2608 . As shown in Figures 4 and 5, by providing the support member 26, a space 2610 that is open inward in the vehicle width direction and in the vehicle fore-and-aft direction is formed between the underside of the bottom wall 1204 of the side frame 12 and the support plate portion 2602.

[0013] As shown in Figures 4 and 5, the end 20A of the battery cross member 20 in the extension direction is inserted into the space 2610 between the underside of the bottom wall 1204 of the side frame 12 and the support plate portion 2602, and is attached by being clamped between the underside of the bottom wall 1204 of the side frame 12 and the support plate portion 2602. In this embodiment, a bushing 28 is attached to the end 20A of the battery cross member 20 in the extension direction, and is inserted into the space 2610 between the underside of the bottom wall 1204 of the side frame 12 and the support plate portion 2602. The bushing 28 is integrated with the end 20A of the battery cross member 20 in the extension direction, and therefore the battery cross member 20 is configured to include the bushing 28. The bushing 28 has an outer tube 2802 connected to the end 20A of the battery cross member 20 in the extension direction, an inner tube 2804 arranged radially inside the outer tube 2802, and an elastic body 2806 provided between the outer tube 2802 and the inner tube 2804. Therefore, in this embodiment, the end 20A in the extension direction of the battery cross member 20 is clamped between the underside of the bottom wall 1204 of the side frame 12 and the support plate portion 2602 by clamping the inner tube 2804 with a bolt B2 inserted through the bolt insertion hole 2608 of the support plate portion 2602, the inner tube 2804, and the underside of the bottom wall 1204 of the side frame 12, and the tip of the bolt B2 is fastened to a weld nut 30 provided on the bottom wall 1204 inside the side frame 12. In addition, the bush 28 can be omitted. In the case where the bush 28 is omitted, a boss portion or a cylindrical portion can be provided at the end 20A of the battery cross member 20 in the extension direction, and the boss portion or the cylindrical portion of the end 20A of the battery cross member 20 in the extension direction can be clamped between the underside of the bottom wall 1204 of the side frame 12 and the support plate portion 2602 using a bolt B2 inserted through the boss portion or the cylindrical portion, the support plate portion 2602, and the bottom wall 1204 of the side frame 12.

[0014] Next, the assembly of the battery pack 14 to the side frame 12 will be described. It is assumed that the battery frame 16 is attached to the battery pack 14 in advance, and that a plurality of support members 26 are joined to the pair of side frames 12. The battery pack 14 is positioned below the pair of side frames 12 so that its longitudinal direction is parallel to the longitudinal direction of the pair of side frames 12, and the bush 28 that constitutes the end 20A of the battery cross member 20 is positioned in front of or behind the space 2610 between the underside of the bottom wall 1204 of the side frame 12 and the support plate portion 2602 in the fore-and-aft direction of the vehicle. Then, the battery pack 14 is moved upward so that the bushings 28 are at the same height as the space 2610, and then the battery pack 14 is moved horizontally toward the front or rear of the vehicle, and the bushings 28 at the ends 20A of each battery cross member 20 are inserted into the space 2610. Next, the battery pack 14 is moved in the longitudinal direction of the side frame 12, and the bushings 28 at the ends 20A of each battery cross member 20 are placed on the support plate portions 2602 of each support member 26. Then, the bushing 28 is slid on the support plate portion 2602 to adjust the position of the bushing 28 relative to the bolt insertion hole 2608 . After positioning, the bolt B2 is inserted from below the support plate portion 2602 through the bolt insertion hole 2608 and the inner cylinder 2804 of the bushing 28 and fastened to the weld nut 30 inside the side frame 12. This completes the assembly of the battery pack 14 to the side frame 12. When removing the battery pack 14 from the side frame 12, the above steps can be generally performed in reverse order.

[0015] According to this embodiment, a support member 26 having a support plate portion 2602 joined to the side frame 12 and facing the underside of the side frame 12 at a predetermined distance in the vertical direction of the vehicle is provided at the location of the side frame 12 where the battery cross member 20 is attached, and the end portion 20A in the extending direction of the battery cross member 20 is attached by being clamped between the underside of the side frame 12 and the support plate portion 2602. Therefore, compared to the conventional structure in which the end of the battery cross member is simply fastened to the side frame with a bolt, the end 20A of the battery cross member 20 in the extension direction is clamped between the underside of the side frame 12 and the support plate portion 2602, which is advantageous in increasing the rigidity of the attachment point of the battery cross member 20 to the side frame 12 and in increasing the durability of the battery pack attachment structure. In addition, since the weight of the battery pack 14 is supported by both the bolt B2 and the support plate portion 2602, the load on the bolt B2 can be reduced, which is advantageous in suppressing deterioration of the bolt B2 and improving the durability of the mounting structure of the battery pack 14.

[0016] In addition, in this embodiment, a bush 28 is attached to the end 20A in the extension direction of the battery cross member 20, and is inserted between the underside of the side frame 12 and the support plate portion 2602.The bush 28 is clamped between the underside of the side frame 12 and the support plate portion 2602 by clamping the inner tube 2804 with a bolt B2 inserted through the support plate portion 2602, the inner tube 2804, and the underside of the side frame 12. Therefore, the bushing 28 can mitigate the vibrations and twists of the vehicle body that occur while the vehicle is running, thereby preventing these vibrations and twists from being transmitted to the battery pack 14, which is advantageous in protecting the battery pack 14. Furthermore, the bushing 28 can reduce vibrations and twists of the battery pack 14 that occur while the vehicle is running, preventing these vibrations and twists from being transmitted to the vehicle body, which is advantageous in improving ride comfort and quietness. Furthermore, the inner tube 2802 of the bushing 28 is firmly clamped between the underside of the side frame 12 and the support plate portion 2602, which is advantageous in increasing the durability of the bushing 28 and is also advantageous in improving ride comfort and quietness.

[0017] Furthermore, in this embodiment, the support member 26 comprises a vertical plate portion 2604 joined to the side surface of the outer side wall 1208 of the side frame 12, and an upper plate portion 2606 extending inward in the vehicle width direction from the upper end of the vertical plate portion 2604 and joined to the upper surface of the upper wall 1202 of the side frame 12, which is more advantageous in improving the attachment strength of the support member 26 to the side frame 12 compared to when the upper plate portion 2606 is not present. This is advantageous in terms of increasing the durability of the battery pack mounting structure.

[0018] In addition, in this embodiment, since multiple support members 26 are provided to match multiple battery cross members 20, the size of each support member 26 can be minimized to a level sufficient to support a battery cross member 20, which is advantageous in terms of reducing the weight of the support members 26.

[0019] (Second embodiment) Next, a second embodiment will be described with reference to FIG. In the following embodiments, parts and members similar to those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and the description will focus on the differences. In the second embodiment, the structure of the support member 26 is different from that in the first embodiment. In the first embodiment, three support members 2602 were provided for each pair of side frames 12, but in the second embodiment, as shown in Figure 6, one support member 2602 is provided for each pair of side frames 12, and the length of the support member 2602 in the fore-and-aft direction of the vehicle is formed to be greater than the distance between the battery cross member 20 located furthest forward of the vehicle and the battery cross member 20 located furthest rearward of the vehicle among the multiple battery cross members 20. In order to simplify the assembly of the battery cross member 20 to the side frame 12, an open downward opening 30 is provided at the rear of the space 2610 where the end 20A of the battery cross member 20 in the extension direction is attached, allowing the end 20A of the battery cross member 20 in the extension direction to be extended from this opening 30 to the height of the space 2610.

[0020] When assembling the battery pack 14 to the side frames 12, as in the first embodiment, the battery pack 14 is positioned below and between the pair of side frames 12 so that its longitudinal direction is parallel to the longitudinal direction of the pair of side frames 12. Then, the battery pack 14 is moved upward to pass the extension end portions 20A of the two front battery cross members 20 through the opening 30 of the support member 26 from below, and the end portions 20A of each battery cross member 20 are raised to the same height as the space portion 2610. Furthermore, the remaining end 20A of the battery cross member 20 in the extension direction is passed through the space behind the support member 26 from below, and the end 20A of the battery cross member 20 is raised to the same height as the space 2610. Next, the battery pack 14 is moved horizontally toward the front of the vehicle, and the bushings 28 at the ends 20A of each battery cross member 20 are inserted into the spaces 2610. Next, the battery pack 14 is moved in the longitudinal direction of the side frame 12, and the bushings 28 at the ends 20A of each battery cross member 20 are placed on the support plate portions 2602 of each support member 26. Then, the bushing 28 is slid on the support plate portion 2602 to adjust the position of the bushing 28 relative to the bolt insertion hole 2608 . After positioning, the bolt B2 is inserted from below the support plate portion 2602 through the bolt insertion hole 2608 and the inner cylinder 2804 of the bushing 28 and fastened to the weld nut 30 inside the side frame 12. This completes the assembly of the battery pack 14 to the side frame 12. When removing the battery pack 14 from the side frame 12, the above steps can be generally performed in reverse order.

[0021] According to the second embodiment, not only can the same effects as those of the first embodiment be achieved, but the length of the support member 2602 in the vehicle's fore-and-aft direction is formed to a dimension greater than the distance between the battery cross member 20 located furthest forward of the vehicle and the battery cross member 20 located furthest rearward of the vehicle among the multiple battery cross members 20, which is more advantageous in terms of increasing the strength and rigidity of the support member 26. This is therefore even more advantageous in improving the mounting strength of the battery cross member 20 to the side frame 12, and is even more advantageous in increasing the durability of the battery pack mounting structure, and is also advantageous in dealing with the increased size and weight of the battery pack 14.

[0022] 10 vehicles 12 Side frame 1202 Upper wall 1204 Bottom wall 1206 Inner side wall 1208 Outer side wall 14 Battery pack 14A Battery Case 1402 bottom 1410 Frame 16 Battery Frame 18 Battery side member 20 Battery cross member 2002 Upper wall 2004 bottom wall 2006 Front side wall 2008 rear wall 20A End in extension direction 22 Connecting member 24 Weld Nut 26 Support member 2602 Support plate part 2604 Vertical plate section 2606 Upper plate 2608 Bolt insertion hole 2610 Space section 28 Bush 2802 Outer cylinder 2804 Inner cylinder 2806 Elastic body 30 Opening Bolt B1 Bolt B2

Claims

1. A plurality of battery cross members are provided on the underside of a battery pack mounted on the vehicle, the cross members extending in the vehicle width direction at intervals in the vehicle front-rear direction, A battery pack mounting structure in which both ends of the plurality of battery cross members in an extension direction are attached to a pair of side frames, a support member is provided which is joined to the side frame and has a support plate portion which faces a lower surface of the side frame at a predetermined interval in the vehicle up-down direction; The end of the battery cross member in the extension direction is sandwiched and attached between the lower surface of the side frame and the support plate portion. A battery pack mounting structure comprising:

2. A bushing is attached to an end of the battery cross member in the extension direction to be inserted between the lower surface of the side frame and the support plate portion, The bushing has an outer cylinder connected to an end of the battery cross member in the extension direction, an inner cylinder arranged radially inside the outer cylinder, and an elastic body provided between the outer cylinder and the inner cylinder, The bushing is sandwiched between the lower surface of the side frame and the support plate by sandwiching the inner tube with a bolt that is inserted through the support plate, the inner tube, and the lower surface of the side frame.

2. The battery pack mounting structure according to claim 1.

3. The support member includes a vertical plate portion extending upward from the support plate portion and joined to an outer surface of the side frame facing outward in the vehicle width direction, and an upper plate portion extending inward in the vehicle width direction from an upper end of the vertical plate portion and joined to an upper surface of the side frame.

2. The battery pack mounting structure according to claim 1.

4. The support member is provided in plurality to match the plurality of battery cross members.

4. The battery pack mounting structure according to claim 1, wherein the battery pack mounting structure is a mounting structure for a battery pack.

5. The support member has a length in the vehicle front-rear direction that is greater than the distance between the battery cross member located furthest forward of the vehicle and the battery cross member located furthest rearward of the vehicle among the plurality of battery cross members, A space portion that is open toward the inside in the vehicle width direction and into which an end portion of the battery cross member can be inserted is provided between the lower surface of the side frame and the support plate portion, The support plate portion has a plurality of openings formed in an open shape on the inner side in the vehicle width direction, and the openings allow the end portions of the battery cross members to be inserted into the space from below, the openings being aligned with the spacing between the plurality of battery cross members.

4. The battery pack mounting structure according to claim 1, wherein the battery pack is mounted on the mounting surface of the battery pack.

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