Battery loading structure in frame vehicle

Abstract

To obtain a battery loading structure in a frame vehicle that can ensure steering stability performance during traveling on a rough road and protect a battery pack in a compatible manner.SOLUTION: A battery loading structure 10 is applied in a frame vehicle 12 that includes: a vehicle body frame 20 including a pair of side rails 14 extending in a vehicle front-rear direction, a first cross member 24 connecting front portions of the side rails 14 in a vehicle width direction, and a second cross member 26 connecting rear portions of the side rails 14 in the vehicle width direction; a sub-frame 30 including a first frame 32 extending in the vehicle front-rear direction at the central part of the vehicle body frame 20 in the vehicle width direction, and a second frame 34 extending in the vehicle width direction at the central part of the first frame 32 in the vehicle front-rear direction, the sub-frame being disposed between the first cross member 24 and the second cross member 26; and a battery pack 40 supported by the sub-frame 30 from a vehicle lower side.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a battery mounting structure in a frame vehicle.

Background Art

[0002] A vehicle body structure of an electric vehicle in which a plurality of cross members extending in the vehicle width direction are installed between a pair of left and right frames extending in the front-rear direction, and a battery pack is disposed above the plurality of cross members has been conventionally known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a frame vehicle, the vehicle body frame serving as the vehicle body skeleton is twisted to ensure steering stability performance during traveling on rough roads. Therefore, when such a frame vehicle is equipped with a battery pack in which a plurality of battery cells are arranged in the front-rear direction and housed in a case, the plurality of battery cells may move in a wavy manner or the case may be damaged due to the twisting of the vehicle body frame. That is, there is a risk that the battery pack may be damaged.

[0005] On the other hand, in order to suppress the damage of the battery pack (protect the battery pack), if a reinforcing member or the like is provided on the vehicle body frame to improve the rigidity of the vehicle body frame, the vehicle body frame becomes difficult to twist, so that the steering stability performance during traveling on rough roads deteriorates. Thus, in a frame vehicle, there is still room for improvement in a structure that achieves both ensuring steering stability performance during traveling on rough roads and protecting the battery pack.

[0006] Therefore, an object of the present invention is to provide a battery mounting structure in a frame vehicle that can achieve both ensuring steering stability performance during driving on rough roads and protecting the battery pack.

Means for Solving the Problems

[0007] To achieve the above object, a battery mounting structure in a frame vehicle according to a first aspect of the present invention includes a pair of left and right side rails extending in the vehicle longitudinal direction, a first cross member connecting the front vehicle side portions of the side rails in the vehicle width direction, and a second cross member connecting the rear vehicle side portions of the side rails in the vehicle width direction, a vehicle body frame having a first frame extending in the vehicle longitudinal direction at the center in the vehicle width direction of the vehicle body frame, and a second frame extending in the vehicle width direction at the center in the vehicle longitudinal direction of the first frame, a sub-frame provided between the first cross member and the second cross member, and a battery pack supported by the sub-frame from below the vehicle.

[0008] According to the invention of the first aspect, a sub-frame having a first frame extending in the vehicle longitudinal direction at the center in the vehicle width direction of the vehicle body frame and a second frame extending in the vehicle width direction at the center in the vehicle longitudinal direction of the first frame is provided between the first cross member and the second cross member of the vehicle body frame. And the battery pack is supported by the sub-frame from below the vehicle.

[0009] Here, the area between the first cross member and the second cross member of the vehicle body frame is an area where the displacement amount due to torsion is extremely small. Therefore, when a sub-frame is provided in that area and the battery pack is supported by the sub-frame, even if the vehicle body frame twists during driving on rough roads or the like, the risk of damage to the battery pack is reduced. That is, according to the present invention, both ensuring steering stability performance during driving on rough roads of the frame vehicle and protecting the battery pack are achieved. Note that the "center in the vehicle longitudinal direction" in the present invention includes the "substantially center in the vehicle longitudinal direction" slightly displaced in the vehicle longitudinal direction from the center in the vehicle longitudinal direction.

[0010] Moreover, the battery mounting structure in the frame vehicle according to the second aspect of the present invention is the battery mounting structure in the frame vehicle according to the first aspect, wherein the sub-frame is provided at the front end portion of the first frame on the vehicle front side and has a first connecting portion extending in the vehicle width direction, and is provided at the rear end portion of the first frame on the vehicle rear side and has a second connecting portion extending in the vehicle width direction. The outer end portion in the vehicle width direction of the first connecting portion and the outer end portion in the vehicle width direction of the second frame are coupled to the side rail, and the outer end portion in the vehicle width direction of the second connecting portion is coupled to the second cross member.

[0011] According to the invention of the second aspect, the sub-frame has a first connecting portion provided at the front end portion of the first frame on the vehicle front side and extending in the vehicle width direction, and a second connecting portion provided at the rear end portion of the first frame on the vehicle rear side and extending in the vehicle width direction. Then, the outer end portion in the vehicle width direction of the first connecting portion and the outer end portion in the vehicle width direction of the second frame are respectively coupled to the side rail, and the outer end portion in the vehicle width direction of the second connecting portion is coupled to the second cross member. Therefore, the battery pack, which is a heavy object, is stably supported by the sub-frame.

[0012] Moreover, the battery mounting structure in the frame vehicle according to the third aspect of the present invention is the battery mounting structure in the frame vehicle according to the second aspect, wherein the battery pack is coupled to the first frame, the second frame, the inner portion in the vehicle width direction of the first connecting portion, and the inner portion in the vehicle width direction of the second connecting portion.

[0013] According to the invention of the third aspect, the battery pack is coupled to the first frame, the second frame, the inner portion in the vehicle width direction of the first connecting portion, and the inner portion in the vehicle width direction of the second connecting portion. Here, the coupling portions of the battery pack to the first frame, the second frame, the inner portion in the vehicle width direction of the first connecting portion, and the inner portion in the vehicle width direction of the second connecting portion are portions within an area where the amount of displacement due to torsion is extremely small. Therefore, even if the vehicle body frame is twisted, the risk of damage to the battery pack is further reduced, and the protection performance for the battery pack is improved.

[0014] Moreover, the battery mounting structure in the frame vehicle according to the fourth aspect of the present invention is the battery mounting structure in the frame vehicle according to any one of the first to third aspects, and the sub-frame is provided above the vehicle body frame on the upper side of the vehicle.

[0015] According to the invention of the fourth aspect, the sub-frame is provided above the vehicle body frame on the upper side of the vehicle. Therefore, since the battery pack is greatly separated from the road surface, the protection performance for the battery pack is improved.

[0016] Moreover, the battery mounting structure in the frame vehicle according to the fifth aspect of the present invention is the battery mounting structure in the frame vehicle according to any one of the first to third aspects, and the sub-frame is provided at an intermediate portion in the vertical direction of the vehicle body frame.

[0017] According to the invention of the fifth aspect, the sub-frame is provided at an intermediate portion in the vertical direction of the vehicle body frame. Therefore, the passenger compartment space becomes wider, and since the battery pack is separated from the road surface, the protection performance for the battery pack is improved.

[0018] Moreover, the battery mounting structure in the frame vehicle according to the sixth aspect of the present invention is the battery mounting structure in the frame vehicle according to any one of the first to third aspects, and the sub-frame is provided below the vehicle body frame on the lower side of the vehicle.

[0019] According to the invention of the sixth aspect, the sub-frame is provided below the vehicle body frame on the lower side of the vehicle. Therefore, the battery pack is disposed on the inner side of the vehicle body frame. Thereby, the mounting stability performance of the battery pack is improved, and the protection performance for the battery pack at the time of collision of the frame vehicle is improved.

[0020] Moreover, the battery mounting structure in the frame vehicle according to the seventh aspect of the present invention is the battery mounting structure in the frame vehicle according to any one of the first to sixth aspects, and the first frame is made to have higher rigidity than the second frame.

[0021] According to the invention of the seventh aspect, the first frame is made to have higher rigidity than the second frame. Therefore, when the frame vehicle travels on a rough road or the like, even if the vehicle body frame twists, it is possible to suppress the plurality of battery cells housed side by side in the front-rear direction in the battery pack from moving in a wavy manner.

[0022] Moreover, the battery mounting structure in the frame vehicle according to the eighth aspect of the present invention is the battery mounting structure in the frame vehicle according to any one of the second to sixth aspects, and the sub-frame is configured by integrally molding at least the first frame and the second frame.

[0023] According to the invention of the eighth aspect, the sub-frame is configured by integrally molding at least the first frame and the second frame. Therefore, compared with the case where the first frame and the second frame are not integrally molded, the moldability of the sub-frame is improved and the number of parts is reduced.

Effect of the Invention

[0024] As described above, according to the present invention, in a frame vehicle, it is possible to achieve both ensuring the steering stability performance during traveling on a rough road and protecting the battery pack.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For the sake of convenience of explanation, in each figure, the arrow UP shown as appropriate is the upward direction of the vehicle, the arrow FR is the forward direction of the vehicle, and the arrow RH is the right direction of the vehicle. Also, in the following description, when the directions of up and down, front and back, and left and right are described without special mention, they indicate up and down in the vertical direction of the vehicle, front and back in the longitudinal direction of the vehicle, and left and right in the left and right direction (vehicle width direction) of the vehicle.

[0027] As shown in FIG. 1, the frame vehicle 12 equipped with the battery mounting structure 10 according to the present embodiment is mainly a battery electric vehicle (BEV) or a fuel cell electric vehicle (FCEV). The frame vehicle 12 has a pair of left and right side rails 14 arranged on both sides in the vehicle width direction and extending in the front-rear direction. Each side rail 14 is formed in a closed cross-sectional shape in a cross-sectional view along the vehicle width direction. Note that front wheels and rear wheels (not shown) are respectively arranged on the outer sides in the vehicle width direction of the front portion 14A side and the rear portion 14B side of each side rail 14.

[0028] Also, as shown in FIG. 2, since a suspension unit (not shown) and the like are arranged on the lower side of the front portion 14A side and the rear portion 14B side of each side rail 14, in a side view seen from the vehicle width direction, they are arranged above the central portion 14C side of each side rail 14. That is, the front portion 14A side and the rear portion 14B side of each side rail 14 each have an inclined portion that inclines upward from the central portion 14C side toward the front upper side and the rear upper side, and extends from each inclined portion toward the front side and the rear side, respectively.

[0029] Further, at the front end of each side rail 14, a front bumper reinforcement 16 extending along the substantially vehicle width direction is installed (see also FIG. 1), and at the rear end of each side rail 14, a rear bumper reinforcement (not shown) extending along the substantially vehicle width direction is installed. Note that energy absorption members such as crush boxes (not shown) may be provided between the front end of each side rail 14 and the front bumper reinforcement 16 and between the rear end of each side rail 14 and the rear bumper reinforcement, respectively.

[0030] As shown in FIG. 1, a plurality of cross members extending in the vehicle width direction are installed between the side rails 14 between the front bumper reinforcement 16 and the rear bumper reinforcement. Specifically, on the front portion 14A side of each side rail 14, cross members 22, 23, 24 connecting the front portion 14A side are installed, and on the rear portion 14B side of each side rail 14, three cross members 26, 27, 28 connecting the rear portion 14B side are installed.

[0031] Each of the cross members 22, 23, 24 and each of the cross members 26, 27, 28 are formed in a closed cross-sectional shape or a substantially inverted "U" shape with the lower side open in a cross-sectional view along the front-rear direction. And the cross members 22, 23, 24 and each of the cross members 26, 27, 28 and the side rails 14 form a ladder-type vehicle body frame 20.

[0032] In the following, among the cross members 22, 23, 24 connecting the front portion 14A side of each side rail 14, the rearmost cross member 24 is referred to as the "first cross member 24", and among the three cross members 26, 27, 28 connecting the rear portion 14B side of each side rail 14, the foremost cross member 26 is referred to as the "second cross member 26".

[0033] Further, a motor for the front wheels (not shown) is supported via a motor mount by the first cross member 24 and the cross member 23 on the front side thereof, and a motor for the rear wheels (not shown) is supported via a motor mount by the second cross member 26 and the cross member 27 on the rear side thereof. Further, a cab (body) not shown is attached to each side rail 14, and a plurality of connection portions 18 for that purpose are provided on the outer surface of each side rail 14.

[0034] In the frame vehicle 12 having the vehicle body frame 20 as described above, a battery pack 40 is mounted on the center side in the front-rear direction (between the wheelbases) of the vehicle body frame 20. Therefore, next, the battery mounting structure 10 for supporting the battery pack 40 will be described in detail. In FIGS. 2 and FIGS. 7 and 8 described later, illustration of the connection portion 18 on the center portion 14C side and the rear portion 14B side of the side rail 14 and illustration of fastening means such as bolts are omitted.

[0035] As shown in FIGS. 1 and 2, a sub-frame 30 formed of high-tensile steel material or the like is provided above the vehicle body frame 20 between the first cross member 24 and the second cross member 26. As shown in FIG. 3, the sub-frame 30 has a first frame 32 extending in the front-rear direction at the center in the vehicle width direction of the vehicle body frame 20, and a second frame 34 extending in the vehicle width direction at substantially the center in the front-rear direction of the first frame 32.

[0036] That is, this sub-frame 30 is configured in a substantially “+” shape in plan view by the first frame 32 and the second frame 34, and the first frame 32 and the second frame 34 are integrally joined by welding or the like. And the 1st flame | frame 32 is comprised so that rigidity may become higher than the 2nd flame | frame 34. Specifically, for example, the first frame 32 is formed with a thicker plate thickness than the second frame 34 or is formed in a hat-shaped cross section.

[0037] Further, as shown in FIGS. 1 and 3, the sub-frame 30 has a first connecting portion 36 extending substantially in the vehicle width direction and a second connecting portion 38 extending substantially in the vehicle width direction. The first connecting portion 36 is provided by integrally joining the central portion in the vehicle width direction thereof to the front end portion (front side end portion) of the first frame 32 by welding or the like. The second connecting portion 38 is provided by integrally joining the central portion in the vehicle width direction thereof to the rear end portion (rear side end portion) of the first frame 32 by welding or the like.

[0038] Further, the first connecting portion 36 is formed in a substantially curved shape that is convex toward the rear side in plan view. More specifically, the first connecting portion 36 extends linearly by a predetermined length from the central portion in the vehicle width direction to the outside in the vehicle width direction, and is formed in a shape that extends linearly by a predetermined length from the outside end portion in the vehicle width direction of the linearly extending portion to the front outside in the vehicle width direction.

[0039] Similarly, the second connecting portion 38 is formed in a substantially curved shape that is convex toward the front side in plan view. More specifically, the second connecting portion 38 extends linearly by a predetermined length from the central portion in the vehicle width direction to the outside in the vehicle width direction, extends linearly by a predetermined length from the outside end portion in the vehicle width direction of the linearly extending portion to the rear outside in the vehicle width direction, and extends linearly by a predetermined length from the outside end portion in the vehicle width direction of the linearly extending portion to the rear side (a shape that is substantially "C" shaped in plan view).

[0040] Further, as indicated by "○" in FIGS. 1 and 4, the outside end portions in the vehicle width direction of the first connecting portion 36 are fastened (coupled) to the upper surfaces of the front portions 14A of the respective side rails 14 and the upper surfaces of the flange portions 14D that project inward in the vehicle width direction from the upper surfaces by fastening means such as, for example, a total of two bolts from the upper side. And the outside end portions in the vehicle width direction of the second connecting portion 38 are fastened (coupled) to the outside end portions in the vehicle width direction on the upper surface of the second cross member 26 by fastening means such as, for example, two bolts arranged in the front-rear direction from the upper side.

[0041] Further, the outer end portion in the vehicle width direction of the second frame 34 is integrally provided so as to project outward in the vehicle width direction from the upper surface on the center portion 14C side of each side rail 14 and the upper surface of the projecting portion 15 (see also FIG. 2), and is fastened (joined) to each of them from above by fastening means such as bolts, for example, a total of three (one for the projecting portion 15 and one for each of the side rails 14 on both the front and rear sides thereof). Therefore, as shown in FIG. 3, a plurality of through holes 34B, 36B, and 38B are formed in the second frame 34, the first connecting portion 36, and the second connecting portion 38, respectively.

[0042] Here, the area between the first cross member 24 and the second cross member 26 in the vehicle body frame 20 (which may include the front end portion of the second cross member 26) is an area where the torsional deformation generated in the vehicle body frame 20 is extremely small when the frame vehicle 12 travels on a rough road. In particular, the central portion in the vehicle width direction and the substantially central portion in the front-rear direction between the first cross member 24 and the second cross member 26 are "nodes of torsion" where the displacement amount due to torsion is 0.

[0043] That is, this subframe 30 is provided in an area where the displacement amount due to torsion in the vehicle body frame 20 is extremely small, and the first frame 32 and the second frame 34 are respectively arranged at the "nodes of torsion". In the following, an area having a substantially rhombic shape in plan view (indicated by a virtual line in FIG. 4) connecting the central portion in the front-rear direction at the center in the vehicle width direction of the first connecting portion 36, the central portion in the front-rear direction at the center in the vehicle width direction of the second connecting portion 38, and the outer end portion in the vehicle width direction of the second frame 34 is referred to as "area E".

[0044] Inside this area E, among the areas where the displacement amount due to torsion in the vehicle body frame 20 is extremely small, it is an area with an even smaller displacement amount. The fastening means (through holes 34B) such as bolts for fastening the outer end portion in the vehicle width direction of the second frame 34 to each projecting portion 15 and each side rail 14 are located on the virtual line defining the area E (see FIG. 4).

[0045] Further, the second frame 34 is disposed substantially at the center in the front-rear direction between the first cross member 24 and the second cross member 26 because, due to the shape of the vehicle body frame 20, the "twist node" may slightly shift forward or rearward from the center in the front-rear direction between the first cross member 24 and the second cross member 26, and this case is included.

[0046] The battery pack 40 is supported by this sub-frame 30 from below (in FIGS. 1 and 4, the battery pack 40 is shown by a phantom line). Specifically, the battery pack 40 is fastened (coupled) to the inner side in the vehicle width direction of the first frame 32, the second frame 34, the first connecting portion 36, and the second connecting portion 38. Here, regarding the configuration of the battery pack 40, as shown in FIG. 5, the battery pack 40 has a rectangular box-shaped case 42 that houses a plurality of battery cells 50 arranged in the front-rear direction.

[0047] The case 42 has a bottom wall (not shown) with a predetermined thickness, left and right side walls 44 with a predetermined thickness, a front wall 46 and a rear wall 48 with a predetermined thickness, and a top wall (not shown) with a predetermined thickness. And on the bottom wall of the case 42, there are a partition plate 52 as a partition member with a predetermined thickness that extends in the front-rear direction and partitions left and right at least at the center in the vehicle width direction, and a partition plate 54 as a partition member with a predetermined thickness that extends in the vehicle width direction and partitions front and rear at substantially the center in the front-rear direction of the partition plate 52, and they are integrally erected at a predetermined height (a height close to the top wall). That is, the left and right side walls 44, the front wall 46, the rear wall 48, and the partition plates 52 and 54 each have rigidity capable of withstanding fastening by fastening means such as bolts.

[0048] Therefore, as shown by "●" in FIGS. 1 and 4, the first frame 32 and the partition plate 52 are fastened (coupled) by fastening means such as a plurality of (for example, 4 in a predetermined interval in the front-rear direction) bolts, and the second frame 34 and the partition plate 54 are fastened (coupled) by fastening means such as a plurality of (for example, 2 in a predetermined interval in the vehicle width direction) bolts.

[0049] More specifically, the front half of the first frame 32 on the front side of the second frame 34 is fastened at two locations spaced apart by a predetermined interval in the front-rear direction, and the rear half of the first frame 32 on the rear side of the second frame 34 is fastened at two locations spaced apart by a predetermined interval in the front-rear direction. And, the inner portion in the vehicle width direction of the second frame 34 is fastened at two locations spaced apart by a predetermined interval in the vehicle width direction.

[0050] Also, the inner portion in the vehicle width direction of the first connecting portion 36 formed linearly in the vehicle width direction and the front wall 46 are fastened (joined) by fastening means such as a plurality of bolts (for example, two bolts spaced apart by a predetermined interval in the vehicle width direction), and the inner portion in the vehicle width direction of the second connecting portion 38 formed linearly in the vehicle width direction and the rear wall 48 are fastened (joined) by fastening means such as a plurality of bolts (for example, two bolts spaced apart by a predetermined interval in the vehicle width direction).

[0051] And, the outer end portions in the vehicle width direction of the second frame 34 (inner portions in the vehicle width direction from the portions fastened to the respective side rails 14) and the left and right side walls 44 are respectively fastened (joined) by fastening means such as a plurality of bolts (for example, three bolts spaced apart by a predetermined interval in the front-rear direction). Therefore, as shown in FIG. 3, a plurality of through holes 32A, 34A, 36A, 38A are formed in the first frame 32, the second frame 34, the first connecting portion 36, and the second connecting portion 38, respectively.

[0052] Next, the operation of the battery mounting structure 10 in the frame vehicle 12 according to the present embodiment configured as described above will be described.

[0053] As described above, a sub-frame 30 having a first frame 32 extending in the front-rear direction at the center in the vehicle width direction of the vehicle body frame 20 and a second frame 34 extending in the vehicle width direction at substantially the center in the front-rear direction of the first frame 32 is provided between the first cross member 24 and the second cross member 26 of the vehicle body frame 20. And, the battery pack 40 is supported by the sub-frame 30 from below.

[0054] Here, the area between the first cross member 24 and the second cross member 26 of the vehicle body frame 20 is an area where the displacement due to torsion is extremely small. Therefore, if the sub-frame 30 is provided in that area and the battery pack 40 is supported by the sub-frame 30, even when the vehicle body frame 20 tramps and twists during driving on rough roads or the like, the battery pack 40 can be suppressed from twisting, so that the risk of damage to the battery pack 40 can be reduced.

[0055] Fig. 6 shows a graph comparing the torsional displacements acting on the battery pack 40. The "torsional displacement" referred to here is the ratio of the distance along the vertical direction between the highest part and the lowest part when the front end and the rear end of the case 42 rotate in opposite directions (i.e., twist) around a virtual central axis extending in the front-rear direction at the center in the vehicle width direction and at the center in the height direction of the battery pack 40, with the monocoque vehicle shown as "5" in a front view or a rear view. As shown in this Fig. 6, the torsional displacement acting on the battery pack 40 supported by the battery mounting structure 10 according to the present embodiment is smaller than that in the case of a monocoque vehicle which is generally more difficult to twist (has a smaller torsional displacement) than a frame vehicle (conventional).

[0056] Thus, according to the battery mounting structure 10 according to the present embodiment, it is possible to achieve both ensuring the steering stability performance during driving on rough roads of the frame vehicle 12 and protecting the battery pack 40. Moreover, since the battery mounting structure 10 according to the present embodiment only needs to provide the sub-frame 30 in an area (torsion node) where the displacement due to torsion in the vehicle body frame 20 is extremely small, a large increase in mass and an increase in manufacturing cost can also be suppressed, and weight reduction and cost reduction in the frame vehicle 12 can also be achieved.

[0057] Further, the sub-frame 30 has a first connecting portion 36 provided at the front end portion of the first frame 32 and extending in the vehicle width direction, and a second connecting portion 38 provided at the rear end portion of the first frame 32 and extending in the vehicle width direction. The outer ends in the vehicle width direction of the first connecting portion 36 and the second frame 34 are respectively fastened (connected) to the side rails 14 (including the flange portion 14D and the overhanging portion 15), and the outer end in the vehicle width direction of the second connecting portion 38 is fastened (connected) to the second cross member 26. Therefore, the sub-frame 30 can stably support the heavy battery pack 40.

[0058] Also, the battery pack 40 is fastened (connected) to the first frame 32, the second frame 34, the inner portion in the vehicle width direction of the first connecting portion 36, and the inner portion in the vehicle width direction of the second connecting portion 38 (see "●" in FIG. 4). Here, the fastening site (connection site) of the battery pack 40 to the first frame 32, the second frame 34, the inner portion in the vehicle width direction of the first connecting portion 36, and the inner portion in the vehicle width direction of the second connecting portion 38 is a site within an area where the displacement amount due to torsion is extremely small.

[0059] In particular, the first frame 32 and the second frame 34 are located at the "nodes of torsion", and the fastening site (connection site) of the battery pack 40 between the first frame 32 and the second frame 34 is located within an area E where the displacement amount is even smaller among the areas where the displacement amount due to torsion is extremely small. Therefore, even when the vehicle body frame 20 is twisted during driving on a rough road or the like, the risk of damage to the battery pack 40 can be further reduced, and the protection performance for the battery pack 40 can be improved.

[0060] In addition, this sub-frame 30 is provided above the vehicle body frame 20. Therefore, the battery pack 40 can be greatly separated from the road surface, so that the protection performance for the battery pack 40 can be improved. Further, the first frame 32 has higher rigidity than the second frame 34. Therefore, even when the vehicle body frame 20 is twisted during traveling on a rough road or the like of the frame vehicle 12, it is possible to suppress the plurality of battery cells 50 housed side by side in the front-rear direction in the battery pack 40 (case 42) from moving in a wavy manner.

[0061] The operation of the battery mounting structure 10 according to the present embodiment is as described above. However, the sub-frame 30 may be provided at an intermediate portion in the vertical direction of the vehicle body frame 20 as in the first modification shown in FIG. 7. Specifically described, the outer ends in the vehicle width direction of the first connecting portions 36 are respectively fastened (coupled) from above by fastening means such as, for example, two bolts to flange portions 14E projecting inward in the vehicle width direction from an intermediate portion in the vertical direction on the inner surface facing the inner side in the vehicle width direction of the front portion 14A side of each side rail 14.

[0062] Similarly, the outer ends in the vehicle width direction of the second connecting portions 38 are respectively fastened (coupled) from above by fastening means such as, for example, two bolts to flange portions 14F projecting inward in the vehicle width direction from an intermediate portion in the vertical direction on the inner surface facing the inner side in the vehicle width direction of the rear portion 14B side of each side rail 14. And the outer ends in the vehicle width direction of the second frame 34 are respectively fastened (coupled) from above by fastening means such as, for example, three bolts to flange portions 14G projecting inward in the vehicle width direction from an intermediate portion in the vertical direction on the inner surface facing the inner side in the vehicle width direction of the central portion 14C side of each side rail 14.

[0063] As a result, in a side view, the sub-frame 30 is disposed on the inner side of the vehicle body frame 20 (side rail 14) without protruding upward and downward beyond the vehicle body frame 20. Therefore, compared with the case of the above-described embodiment, since the sub-frame 30 (battery pack 40) has moved downward, a wider vertical space on the passenger compartment side can be secured. Further, compared with the case of the above-described embodiment, although the sub-frame 30 moves downward, since the battery pack 40 can be separated from the road surface, the protection performance for the battery pack 40 can be improved.

[0064] Although not shown, when the second cross member 26 is formed in a closed cross-sectional shape, the outer ends in the vehicle width direction of the second connecting portion 38 may be fastened (coupled) to the outer ends in the vehicle width direction on the lower surface of the second cross member 26 from below by fastening means such as, for example, two bolts. At this time, if the height position of the lower surface of the second cross member 26 is not an appropriate height position, the second cross member 26 may appropriately change its height.

[0065] Further, the sub-frame 30 may be provided below the vehicle body frame 20 as in the second modification shown in FIG. 8. More specifically, the outer ends in the vehicle width direction of the first connecting portion 36 are respectively fastened (coupled) from below by fastening means such as, for example, a total of two bolts to the lower surface of the front portion 14A side of each side rail 14 and a flange portion 14H projecting inward in the vehicle width direction from the lower surface.

[0066] Further, the outer ends in the vehicle width direction of the second connecting portion 38 are respectively fastened (coupled) from below by fastening means such as, for example, a total of two bolts to the flange portions 14J projecting inward in the vehicle width direction from the lower surface of the rear portion 14B side of each side rail 14. Then, the outer ends in the vehicle width direction of the second frame 34 are respectively fastened (coupled) from below by fastening means such as, for example, a total of three bolts to the lower surface of the central portion 14C side of each side rail 14 and the lower surface of the overhang portion 17 formed upside down with respect to the overhang portion 15.

[0067] As a result, since the sub-frame 30 is disposed below the vehicle body frame 20 (side rail 14) in a side view, the battery pack 40 is disposed inside the vehicle body frame 20. In other words, at least a part of the battery pack 40 (case 42) in the height direction overlaps with the vehicle body frame 20 in a side view, and at least a part of the left and right side walls 44, the front wall 46, and the rear wall 48 of the battery pack 40 (case 42) in the height direction is surrounded by the vehicle body frame 20.

[0068] Therefore, the mounting stability performance of the battery pack 40 can be improved, and the protection performance for the battery pack 40 during a collision of the frame vehicle 12 can be improved. That is, even when a collision load is input to the frame vehicle 12 from the front-rear direction or the vehicle width direction, the battery pack 40 can be more effectively protected from the collision load.

[0069] Although illustration is omitted as described above, when the second cross member 26 is formed in a closed cross-sectional shape, the outer ends in the vehicle width direction of the second connecting portion 38 may be fastened (joined) to the outer ends in the vehicle width direction of the lower surface of the second cross member 26 from below by fastening means such as, for example, two bolts. At that time, if the height position of the lower surface of the second cross member 26 is not an appropriate height position, the second cross member 26 may appropriately change its height.

[0070] Further, the sub-frame 30 is not limited to being configured by integrally joining the first frame 32, the second frame 34, the first connecting portion 36, and the second connecting portion 38 by welding or the like. Among the first frame 32, the second frame 34, the first connecting portion 36, and the second connecting portion 38, at least the first frame 32 and the second frame 34 may be integrally formed. According to this, compared with the case where the first frame 32 and the second frame 34 are not integrally formed, the formability (dimensional accuracy) of the sub-frame 30 can be improved, and the number of parts can be reduced.

[0071] As described above, the battery mounting structure 10 of the frame vehicle 12 according to the present embodiment has been described with reference to the drawings. However, the battery mounting structure 10 of the frame vehicle 12 according to the present embodiment is not limited to that shown in the drawings, and can be appropriately designed and changed within the scope not departing from the gist of the present invention. For example, in the sub-frame 30, the first frame 32 and the second frame 34 may be integrally formed by fastening, adhesion, etc., or the first frame 32, the first connecting portion 36, and the second connecting portion 38 may be integrally formed by fastening, adhesion, etc., respectively.

[0072] Also, although not shown, the battery pack 40 may be fastened (coupled) so as to be suspended from the sub-frame 30. In this case, the partition plates 52 and 54 may be integrally vertically provided from the top wall of the case 42 at a predetermined height (a height close to the bottom wall). Also, in this case, from the viewpoint of protecting the battery pack 40, it is preferable that an under cover having higher strength than usual is provided below the battery pack 40.

Explanation of Reference Numerals

[0073] 10 Battery mounting structure 12 Frame vehicle 14 Side rail 20 Vehicle body frame 24 First cross member 26 Second cross member 30 Sub-frame 32 First frame 34 Second frame 36 First connecting portion 38 Second connecting portion 40 Battery pack

Claims

1. A vehicle body frame having a pair of left and right side rails extending in the longitudinal direction of the vehicle, a first cross member connecting the front side portions of the side rails in the vehicle width direction, and a second cross member connecting the rear side portions of the side rails in the vehicle width direction, A first frame extending in the longitudinal direction of the vehicle at the center in the vehicle width direction of the vehicle body frame, and a second frame extending in the vehicle width direction at the center in the longitudinal direction of the first frame, and a sub-frame provided between the first cross member and the second cross member, A battery pack supported from below the vehicle on the sub-frame, A battery mounting structure in a framed vehicle comprising the above.

2. The sub-frame is Provided at the front side end in the longitudinal direction of the first frame and having a first connecting portion extending in the vehicle width direction, Provided at the rear side end in the longitudinal direction of the first frame and having a second connecting portion extending in the vehicle width direction, And has A battery mounting structure in a framed vehicle according to claim 1, wherein an outer end in the vehicle width direction of the first connecting portion and an outer end in the vehicle width direction of the second frame are coupled to the side rail, and an outer end in the vehicle width direction of the second connecting portion is coupled to the second cross member.

3. A battery mounting structure in a framed vehicle according to claim 2, wherein the battery pack is coupled to the first frame, the second frame, an inner portion in the vehicle width direction of the first connecting portion, and an inner portion in the vehicle width direction of the second connecting portion.

4. A battery mounting structure in a framed vehicle according to claim 3, wherein the sub-frame is provided above the vehicle body frame.

5. A battery mounting structure in a framed vehicle according to claim 3, wherein the sub-frame is provided at an intermediate portion in the vertical direction of the vehicle body frame.

6. The battery mounting structure in the frame vehicle according to claim 3, wherein the sub-frame is provided on the lower side of the vehicle body frame.

7. The battery mounting structure in the frame vehicle according to any one of claims 1 to 6, wherein the first frame is made to have higher rigidity than the second frame.

8. The battery mounting structure in the frame vehicle according to any one of claims 2 to 6, wherein the sub-frame is configured such that at least the first frame and the second frame are integrally formed.

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