Vehicle lower structure

Abstract

To provide a vehicle lower structure capable of selectively manufacturing a floor panel-less vehicle and a non-floor panel-less vehicle when desiring to mount battery cells with different terminal disposing positions on the same platform.SOLUTION: A vehicle lower structure 10 comprises: a pair of vehicle body skeleton members 12 extending in a vehicle front and rear direction on both sides of a vehicle in a vehicle width direction; a battery pack 20 disposed between the pair of vehicle body skeleton members 12, and having a battery case 21 in which one or more battery cells are accommodated; and attachment parts 40 protruded from the pair of vehicle body skeleton members 12 toward the inner sides in a vehicle width direction above the battery pack 20, and capable of placing a floor panel 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle undercarriage. [Background technology]

[0002] Patent Document 1 listed below discloses a structure in which a service disconnect switch that is manually operated to mechanically cut off the battery high-voltage circuit is disposed on the upper surface of a battery mounted under the floor of a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-139522 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when the upper case of the battery (battery pack) forms the vehicle floor, a load may be applied to the battery cells due to input from above. In this case, battery cells with terminals located on the upper side require a floor panel to prevent short circuits when input is received from above. Therefore, when it is desired to mount battery cells with different terminal locations on the same platform, it becomes necessary to produce vehicles that do not have a floor panel and vehicles that do not have a floor panel.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a vehicle undercarriage structure that can be used to create vehicles that are floor panel-less and vehicles that are not, when it is desired to mount battery cells with different terminal placement positions on the same platform. [Means for solving the problem]

[0006] The vehicle undercarriage structure of the first aspect comprises a pair of body frame members extending in the fore-and-aft direction of the vehicle on both sides of the vehicle in the vehicle width direction, a battery pack arranged between the pair of body frame members and having one or more battery cells housed inside a battery case, and mounting portions each protruding from the pair of body frame members toward the inside of the vehicle width direction above the battery pack and on which a floor panel can be placed.

[0007] The vehicle undercarriage structure according to the first aspect includes mounting portions on the upper side of the battery pack that protrude inward in the vehicle width direction from the pair of vehicle body frame members and that can accommodate a floor panel, allowing the floor panel to be attached from the rear. This makes it possible to mount a floor panel when necessary, so that when it is desired to mount battery cells with different terminal locations on the same platform, it is possible to create vehicles that are floor-panel-less and vehicles that are not.

[0008] The vehicle undercarriage structure of the second aspect, in the configuration described in the first aspect above, comprises two or more cross members that are spanned across the pair of body frame members, and two cross members adjacent in the fore-and-aft direction of the vehicle protrude toward opposing surfaces and have second mounting portions on which the floor panel can be placed.

[0009] In a vehicle undercarriage structure according to a second aspect, two or more cross members that are adjacent in the vehicle longitudinal direction among two or more cross members that are installed across a pair of vehicle body frame members are provided with second mounting portions that protrude toward the opposing surfaces and on which a floor panel can be placed, thereby increasing the stability of the floor panel when placed on the second mounting portions.

[0010] A vehicle undercarriage structure according to a third aspect is the configuration according to the first or second aspect, wherein the mounting portion is integrally formed with the vehicle body frame member.

[0011] In the vehicle undercarriage structure according to the third aspect, the mounting portion is integrally formed with the body frame member, and therefore the number of parts and assembly steps can be reduced compared to a structure in which the mounting portion is formed separately from the body frame member.

[0012] A vehicle undercarriage structure according to a fourth aspect is configured as described in the first or second aspect above, wherein the mounting portion is fastened to the body frame member by a fastening member that can be fastened from one side.

[0013] In the vehicle undercarriage structure according to the fourth aspect, the mounting portion is fastened to the vehicle body frame member by a fastening member that can be fastened from one side, so that the mounting portion can be fastened from the inside of the vehicle body frame member, thereby improving workability in installing the mounting portion.

[0014] The vehicle undercarriage structure according to the fifth aspect is configured as described in any one of the first to fourth aspects, wherein the mounting portion is configured as an L-shaped member having an attachment surface to the body frame member and a support surface for the floor panel.

[0015] In the vehicle undercarriage structure according to the fifth aspect, the mounting portion is composed of an L-shaped member having an attachment surface to the body frame member and a support surface for the floor panel, and therefore costs can be reduced by making the mounting portion of a simple structure. [Effects of the Invention]

[0016] As described above, the vehicle undercarriage structure of the present invention has the excellent effect of making it possible to manufacture vehicles that are floor panel-less and vehicles that are not floor panel-less, when it is desired to mount battery cells with different terminal arrangement positions on the same platform. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an exploded perspective view showing a schematic view of a part of a vehicle undercarriage structure according to an embodiment of the present invention. [Figure 2]2 is a cross-sectional view schematically showing a state in which the device is not disassembled, taken along line 2-2 in FIG. 1. FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view showing the main part of FIG. 2 in an enlarged manner. [Figure 4] 4 is an enlarged cross-sectional view of a main part corresponding to FIG. 3, showing a modified example of the mounting portion. FIG. [Figure 5] 1 is a cross-sectional view schematically showing a vehicle underbody structure of a conventional vehicle that is not floor panel-less. [Figure 6] FIG. 1 is a cross-sectional view schematically showing a vehicle underbody structure of a conventional floor panel-less vehicle. [Figure 7] FIG. 1 is a cross-sectional view illustrating a problem in a conventional floor panel-less vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0018] A vehicle underbody structure 10 according to one embodiment of the present invention will be described with reference to the drawings.

[0019] FIG. 1 is an exploded perspective view schematically showing a portion of a vehicle underbody structure 10 according to an embodiment. Note that the arrows FR, UP, and RH in the figure respectively indicate the vehicle forward direction, vehicle upward direction, and vehicle rightward direction of a vehicle to which the vehicle underbody structure 10 is applied. In the following description, unless otherwise specified, the terms "front-rear," "up-down," and "left-right" refer to front-rear in the vehicle fore-and-aft direction, up-down in the vehicle up-and-down direction, and left-right in the vehicle left-right direction (width direction), respectively. Also, the arrow IN in the figure indicates the inside in the vehicle width direction or the inside in the vehicle fore-and-aft direction of a vehicle to which the vehicle underbody structure 10 is applied.

[0020] As shown in Figure 1, the vehicle undercarriage 10 of this embodiment includes a pair of rockers 12 extending in the longitudinal direction of the vehicle on both sides in the vehicle width direction, a battery pack 20 arranged between the pair of rockers 12, and a mounting portion 40 above the battery pack 20 on which a floor panel 30 can be placed.

[0021] The vehicle undercarriage 10 also includes a front cross member 14 that is provided at the front end of the pair of rockers 12 and to which a front module (not shown) that constitutes the front part of the vehicle is joined, and a rear cross member 16 that is provided at the rear end of the pair of rockers 12 and to which a rear module (not shown) that constitutes the rear part of the vehicle is joined. The front cross member 14 and the rear cross member 16 are each mounted across the pair of rockers 12.

[0022] The vehicle undercarriage 10 also includes a first cross member 18 and a second cross member 19 located between the front cross member 14 and the rear cross member 16 and in the vehicle longitudinal center of the rocker 12. The first cross member 18 and the second cross member 19 each extend in the vehicle width direction and are installed between the pair of left and right rockers 12. Furthermore, front vehicle seats (not shown) are attached to the first cross member 18 and the second cross member 19, as an example.

[0023] FIG. 2 is a cross-sectional view schematically showing a state in which the rocker 12 is cut along line 2-2 in FIG. 1 in an unexploded state. As shown in FIG. 2, the rocker 12 is a vehicle body frame member formed in a substantially rectangular closed cross section. The rocker 12 has a rocker inner panel 12A located on the inside in the vehicle width direction and a rocker outer panel 12B located on the outside in the vehicle width direction. The rocker inner panel 12A and the rocker outer panel 12B are joined to each other at their respective upper and lower edges, and a closed space extending in the front-rear direction is formed inside the rocker 12. Note that an energy absorbing material or the like may be placed within the closed cross section formed by the rocker inner panel 12A and the rocker outer panel 12B.

[0024] The battery pack 20 is provided in the lower part of the vehicle and houses one or more battery cells 50 inside. The battery pack 20 has a battery case 21 formed in a generally box shape including an upper case 22 and a lower case 24. The upper case 22 is formed in a generally hat shape with the lower side of the vehicle open in a cross section seen from the front-rear direction of the vehicle, and upper flanges 22A are formed at both ends of the upper case 22 in the vehicle width direction, overlapping the lower surfaces of the left and right rockers 12, respectively.

[0025] The lower case 24 is formed in a generally hat shape with an open upper side in a cross section seen from the vehicle longitudinal direction, and lower flanges 24A are formed at both ends of the lower case 24 in the vehicle width direction, overlapping the upper flanges 22A of the upper case 22. The upper flanges 22A and the lower flanges 24A are fastened to the locker 12 from below by fasteners 26 such as bolts. The battery pack 20 may also be formed with a battery cover that covers the battery cells 50 from above. In this case, a member that supports the battery cells 50 from below may be provided instead of the lower case 24.

[0026] A metal panel member 28 serving as a lower load transmission member is provided below the vehicle bottom of the battery pack 20. The panel member 28 extends in the vehicle width direction and the vehicle front-rear direction. The panel member 28 is formed in a generally flat plate shape so as to cover the battery pack 20 from the vehicle bottom.

[0027] A plurality of battery cells 50 are arranged side by side in the vehicle width direction and the vehicle front-rear direction, and each battery cell 50 is, for example, a lithium-ion battery. In this embodiment, as shown in Fig. 2 as an example, the battery cell 50 has a terminal 52 arranged in the vehicle width direction or the vehicle front-rear direction, rather than on the upper side of the vehicle. Note that in the technology disclosed herein, instead of the terminal 52, a terminal 54 arranged on the upper side of the vehicle may be provided as shown by the dotted line in the figure.

[0028] The mounting portions 40 are, for example, L-shaped members and are formed in an elongated shape. In this embodiment, as shown in Fig. 1 as an example, four mounting portions 40 are attached to each of the vehicle front side of the first cross member 18 and the vehicle rear side of the second cross member 19. Specifically, on each of the vehicle front side and the vehicle rear side, the mounting portions 40 are attached to the vehicle width direction inner sides of the pair of rockers 12, and are arranged so as to extend in the vehicle front-rear direction.

[0029] In addition, the mounting portions 40 are attached to the rear surface of the front cross member 14, the front surface of the rear cross member 16, the front surface of the first cross member 18, and the rear surface of the second cross member 19 so as to extend in the vehicle width direction.

[0030] Figure 3 is an enlarged cross-sectional view of the essential parts of Figure 2. As shown in Figure 3, the mounting portion 40 has one end 42 having a mounting surface 42A to be mounted to any one of the rocker inner panel 12A of the rocker 12, the front cross member 14, the rear cross member 16, the first cross member 18, and the second cross member 19. The mounting portion 40 also has another end 44 extending perpendicularly from the end of the one end 42 and having a mounting surface 44A of the floor panel 30.

[0031] One end 42 of the mounting portion 40 is fastened to the above-mentioned mounted member by a fastening member 60 that can be fastened from one side. Specifically, in this embodiment, the one end 42 is fastened to the rocker inner panel 12A of the rocker 12 from the inside in the vehicle width direction by the fastening member 60. The one end 42 is also fastened to the rear cross member 16 and the first cross member 18 from the front side of the vehicle by the fastening member 60. The one end 42 is also fastened to the front cross member 14 and the second cross member 19 from the rear side of the vehicle by the fastening member 60.

[0032] 3, one end 42 is fastened to the attached member by fastening members 60 at two locations in the vehicle vertical direction and at multiple locations set at predetermined intervals in the longitudinal direction of one end 42. Any fastening member may be used as fastening member 60 as long as it can be fastened from one side, and known fastening members may be used.

[0033] 3, the mounting portions 40 fastened to a pair of rockers 12 by fastening members 60 each have the other end 44 protruding inward in the vehicle width direction. The mounting portions 40 fastened to the front cross member 14 and the first cross member 18, which are two cross members adjacent in the vehicle fore-and-aft direction, by fastening members 60 each have the other end 44 protruding toward the opposing surfaces. Similarly, the mounting portions 40 fastened to the rear cross member 16 and the second cross member 19 by fastening members 60 each have the other end 44 protruding toward the opposing surfaces.

[0034] 1, in a vehicle equipped with the vehicle undercarriage 10 of the present embodiment described above, a floor panel 30 is placed, as needed, on the upper surfaces of the four other ends 44 that protrude from the respective attachment members further forward of the first cross member 18. Although not shown, a floor panel 30 is also placed, as needed, on the upper surfaces of the four other ends 44 that protrude from the respective attachment members further rearward of the second cross member 19. The floor panel 30 is a member that constitutes the floor surface of the vehicle compartment, and is formed, for example, from a rectangular plate member.

[0035] In this embodiment, as described above, the rocker 12 and the mounting portion 40 are formed separately. However, the rocker 12 and the mounting portion 40 may be formed integrally. FIG. 4 is an enlarged cross-sectional view of a main portion corresponding to FIG. 3, illustrating a modified mounting portion 40. As shown in FIG. 4, the modified mounting portion 40A is configured with a protruding portion 46 that protrudes elongated from the mounting member, which is the rocker inner panel 12A of the rocker 12, the front cross member 14, the rear cross member 16, the first cross member 18, and the second cross member 19. Specifically, the mounting portions 40A provided on the pair of rockers 12 have the protruding portions 46 protruding inward in the vehicle width direction. Furthermore, the mounting portions 40A provided on the front cross member 14 and the first cross member 18 have the protruding portions 46 protruding toward the opposing surfaces of each other. Similarly, the mounting portions 40 provided on the rear cross member 16 and the second cross member 19 have the protruding portions 46 protruding toward the opposing surfaces of each other.

[0036] (Action and effect) Next, the effects of this embodiment will be described.

[0037] Fig. 5 is a cross-sectional view showing a schematic view of the vehicle undercarriage of a conventional vehicle that is not floor panel-less, Fig. 6 is a cross-sectional view showing a schematic view of the vehicle undercarriage of a conventional floor panel-less vehicle, and Fig. 7 is a cross-sectional view for explaining the problems with the conventional floor panel-less vehicle. In each figure, components similar to those shown in Fig. 2 in the above-described embodiment are designated by the same reference numerals, and their explanation will be omitted here.

[0038] As shown in Figure 5, a conventional vehicle 100 equipped with a floor panel 32 (hereinafter referred to as a floor panel-equipped vehicle) is, as an example, disposed above the upper case 22 of a battery pack 20. The floor panel 32 has flange portions 32A bent upward at both ends in the vehicle width direction, and these flange portions 32A are joined to the rocker inner panel 12A of the rocker 12. In Figure 5, the battery cells 50 housed in the battery pack 20 have terminals 54 disposed on the upper side of the vehicle, but instead of these terminals 54, it is also possible to have terminals disposed in the vehicle width direction or the vehicle longitudinal direction.

[0039] Meanwhile, in recent years, vehicles have become known that have a structure in which the floor panel has been removed and the upper surface of the battery pack functions as the floor panel in order to reduce the number of parts and increase the interior space of the vehicle (hereinafter referred to as a floor-panel-less vehicle). As shown in Fig. 6, in a floor-panel-less vehicle 110, an upper case 122 of a battery pack 120 functions as the floor panel. In the floor-panel-less vehicle 110, the battery cells 50 housed in the battery pack 120 have terminals 52 arranged in the vehicle width direction or the vehicle front-rear direction.

[0040] However, as shown in Figure 7, in a floor panel-less vehicle 110, a load may be applied to a battery cell 50 due to an input from above, as indicated by the black arrow in the figure. In this case, for example, if a battery cell 50 with terminals 54 disposed on the upper side of the vehicle is used, a floor panel 32 such as that shown in Figure 5 is required to prevent a short circuit when an input is applied from above. Therefore, when it is desired to mount battery cells 50 with terminals disposed in different positions on the same platform, it becomes necessary to produce vehicles that are floor panel-less (floor panel-less vehicles) and vehicles that are not floor panel-less (floor panel-equipped vehicles).

[0041] Therefore, the vehicle undercarriage 10 according to this embodiment is provided with mounting sections 40 on which the floor panel 30 can be placed, which protrude from the pair of rockers 12 inward in the vehicle width direction above the battery pack 20, and which allow the floor panel 30 to be placed from the rear using the mounting sections 40. This makes it possible to place the floor panel 30 when necessary, and therefore, when it is desired to mount battery cells 50 with different terminal arrangement positions on the same platform, it is possible to create vehicles that are floor-panel-less and vehicles that are not.

[0042] Furthermore, in the vehicle undercarriage structure 10 according to this embodiment, of the two or more cross members installed across the pair of rockers 12, two cross members adjacent in the fore-and-aft direction of the vehicle (the front cross member 14 and the first cross member 18, and the second cross member 19 and the rear cross member 16) are provided with mounting portions 40 that protrude toward the opposing surfaces and allow the floor panel 30 to be placed thereon. Therefore, the mounting portions 40 can increase the stability of the floor panel 30 when it is placed thereon.

[0043] Furthermore, in the vehicle undercarriage structure 10 according to this embodiment, the mounting portion 40 is fastened to the workpiece by the fastening member 60 that can be fastened from one side, so the mounting portion 40 can be fastened from the inside of the workpiece. This improves the workability in installing the mounting portion 40.

[0044] Furthermore, in the vehicle undercarriage structure 10 according to this embodiment, the mounting portion 40 is composed of an L-shaped member having an attachment surface 42A for the attachment member and a support surface 44A for the floor panel 30, and therefore, by making the mounting portion 40 of a simple structure, costs can be reduced.

[0045] Furthermore, in the above-described modified example, the mounting portion 40A is integrally formed with the member to be mounted, so the number of parts and assembly steps can be reduced compared to a structure in which the mounting portion 40 is formed separately from the member to be mounted.

[0046] [supplementary explanation] In the above-described embodiment, the mounting portion 40 is configured as an L-shaped member, but the present invention is not limited to this. For example, the mounting portion may be a cylindrical member protruding from the mounting surface. In other words, the shape of the mounting portion is not limited as long as it can accommodate the floor panel 30.

[0047] Furthermore, in the above-described embodiment, the mounting portion 40 is attached to the member to be mounted by the fastening member 60, but the present invention is not limited to this, and the mounting portion 40 may be joined by welding or attached by other means.

[0048] Furthermore, the configuration of the present invention is not limited to the above-described embodiment, and the configuration can be changed as appropriate as long as the problem can be solved. [Explanation of symbols]

[0049] 10 Vehicle undercarriage 12 Rocker (body frame member) 14 Front cross member (cross member) 16 Rear cross member (cross member) 18 First cross member (cross member) 19 Second cross member (cross member) 20 Battery pack 21 Battery case 40 Mounting part 40A mounting part 42A Mounting surface 44A Placement surface 60 Fastening members

Claims

1. a pair of vehicle body frame members extending in a front-rear direction of the vehicle on both sides in a vehicle width direction of the vehicle; a battery pack disposed between the pair of vehicle body frame members and having one or more battery cells housed inside a battery case; mounting portions each protruding inward in a vehicle width direction from the pair of vehicle body frame members above the battery pack, on which a floor panel can be placed; A vehicle undercarriage comprising:

2. two or more cross members that are spanned across the pair of body frame members, 2. The vehicle undercarriage structure according to claim 1, wherein two cross members adjacent in the vehicle longitudinal direction are provided with second mounting portions that protrude toward surfaces facing each other and on which the floor panel can be placed.

3. The vehicle underbody structure according to claim 1 , wherein the mounting portion is integrally formed with the vehicle body frame member.

4. The vehicle underbody structure according to claim 1, wherein the mounting portion is fastened to the vehicle body frame member by a fastening member that can be fastened from one side.

5. 2. The vehicle underbody structure according to claim 1, wherein the mounting portion is configured as an L-shaped member having a mounting surface to be attached to the vehicle body frame member and a support surface for the floor panel.

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