Invention name: Automotive substructure
Technical field
[0001]
　The present invention relates to a substructure of an automobile.
Background technology
[0002]
　Conventionally, it is known that a battery mounted on an electric vehicle or the like is housed in a container such as a battery box, and this container is attached to a vehicle body (see, for example, Patent Documents 1 to 6).
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent Application Laid-Open No. 2017-226353
Patent Document 2: Japanese Patent Application Laid-Open No. 2019-14349
Patent Document 3: Japanese Patent Application Laid-Open No. 2019-1560229
Patent Document 4: Patent Document 6122807
Patent Document 5: Patent Document 541125 Japanese Patent
Application Laid-Open No. 2013-060160
Outline of the invention
Problems to be solved by the invention
[0004]
　Since the battery has a high specific density and is relatively heavy, a large load is applied to the battery when a vehicle equipped with the battery collides with the battery. Deformation of a loaded battery can cause the battery to ignite or leak. Therefore, when the battery is housed in a container such as a battery box and attached to the vehicle body, the container needs to have high structural rigidity. This is because if the rigidity of the container is low, the container may be broken and the battery may be deformed in the event of a collision, and the container containing the battery may be detached from the vehicle body.
[0005]
　All of the above-mentioned Patent Documents 1 to 6 disclose a battery box for a vehicle having high rigidity in order to improve collision resistance. For example, the battery pack described in Patent Document 1 includes a high-rigidity member such as a battery cross member and a vertical bone. The battery pack described in Patent Document 2 includes a highly rigid side wall portion, a front wall portion, and a rear wall portion made of an extruded product. The battery pack described in Patent Document 3 includes an in-pack cloth which is a highly rigid skeleton member that protects the battery pack. The battery frame described in Patent Document 4 is provided with a highly rigid second cross member below the ICU. The battery case described in Patent Document 5 includes first to fourth cross members with high rigidity. The battery pack described in Patent Document 6 includes a subcross member in the battery frame.
[0006]
　However, if a container such as a battery box for accommodating a battery has high rigidity, there is a problem that the structure of these containers becomes complicated and the weight of the container increases.
[0007]
　Therefore, it is an object of the present invention to provide an automobile substructure capable of mounting a battery in an automobile with a simple configuration and efficiently transmitting a load at the time of a collision.
Means to solve problems
[0008]
　The gist of this disclosure is as follows.
[0009]
(1) A lower structure of an automobile, comprising a vehicle body floor constituting the floor portion of the automobile, and a battery cell or a battery module directly suspended and fixed from the vehicle body floor below the vehicle body floor.
[0010]
(2) The lower structure of an automobile according to (1) above, wherein the battery cell or the battery module is fixed to the vehicle body floor in a state where the upper surface is in contact with the lower surface of the vehicle body floor.
[0011]
(3) The cooling panel for circulating the cooling liquid is further provided, and the battery cell or the battery module is fixed to the vehicle body floor with the cooling panel interposed between the battery cell or the battery module. The substructure of the automobile described in 1).
[0012]
(4) The lower structure of an automobile according to (3) above, wherein the upper surface of the battery cell or the battery module is in contact with the lower surface of the cooling panel.
[0013]
(5) The vehicle body floor has a floor panel constituting the floor surface of the automobile, and the battery cell or the battery module is fixed to the floor panel, according to the above (1) to (4). The substructure of the vehicle described in either.
[0014]
(6) The vehicle body floor is arranged on the floor panel and has a cross member extending in the left-right direction of the automobile, and the battery cell or the battery module is fixed to the floor panel or the cross member. The substructure of the automobile according to (5) above.
[0015]
(7) The vehicle body floor has a side sill extending in the front-rear direction of the automobile at the outermost side in the left-right direction of the automobile, and the floor panel is provided between the left and right side sill, and the
　battery cell or the battery . The vehicle substructure according to (5) or (6) above, wherein the module is arranged over the entire area of ​​the floor panel including the area adjacent to the side sill.
Effect of the invention
[0016]
　According to the present invention, it is possible to mount a battery in an automobile with a simple configuration, and it is possible to provide an automobile substructure capable of efficiently transmitting a load at the time of a collision.
A brief description of the drawing
[0017]
FIG. 1 is a schematic view for explaining a lower structure of an automobile according to the present embodiment, and is a plan view of the lower structure of the automobile as viewed from above.
[Fig. 2] This is a view of the lower structure of an automobile from below.
FIG. 3 is a schematic view showing a cross section along the alternate long and short dash line I-I'in FIG.
FIG. 4 is a schematic view showing a cross section along the alternate long and short dash line II-II'of FIG.
5 is a schematic view showing a cross section along the alternate long and short dash line III-III' of FIG. 1. FIG.
[Fig. 6] Fig. 6 is a schematic diagram showing an enlarged vicinity of a side sill in FIG.
FIG. 7 is a schematic diagram showing an enlarged vicinity of a side sill in FIG.
FIG. 8 is an enlarged view showing the vicinity of the side sill 20 and is a schematic view showing an example in which a water cooling panel is arranged between the battery and the floor panel.
FIG. 9 is a perspective view showing a state in which the battery and the water cooling panel are viewed from below.
FIG. 10 illustrates how the load path of the load is reduced by the substructure of the present embodiment.
FIG. 11 illustrates how the load path of the load is reduced by the substructure of the present embodiment.
FIG. 12 illustrates how the load path of the load is reduced by the substructure of the present embodiment.
FIG. 13 is a side view showing a hollow member used when comparing load bearing performance.
14 is a schematic view showing a cross section along the alternate long and short dash line IV-IV'in FIG. 13. FIG.
[Fig. 15] Fig. 15 is a characteristic diagram showing a comparison result of load bearing performance between an example and a comparative example.
Embodiment for carrying out the invention
[0018]
　First, with reference to FIGS. 1 to 5, the configuration of the lower structure of the automobile according to the embodiment of the present invention will be described. The automobile lower structure 100 according to the present embodiment relates to a lower structure of an automobile equipped with a battery such as an electric vehicle. This substructure has a structure in which a battery cell or a battery module of an automobile is directly fixed to a member constituting the vehicle body floor of the automobile.
[0019]
　FIG. 1 is a schematic view for explaining the lower structure 100 of the automobile according to the present embodiment, and is a plan view of the lower structure 100 of the automobile as viewed from above. FIG. 2 is a view of the lower structure 100 of the automobile as viewed from below. FIG. 3 is a schematic view showing a cross section along the alternate long and short dash line I-I'in FIG. In FIG. 2, the undercover 18 is not shown.
[0020]
　First, the basic structure of the vehicle body floor 110 in the lower structure 100 of the automobile will be described. As shown in FIG. 1, the vehicle body floor 110 includes a floor panel 12, floor cross members 14a to 14f, front bumper 15, front side members 16a and 16b, rear side members 17a and 17b, undercover 18, rear bumper 19, side sill 20 and the like. have.
[0021]
　The side sill 20 extends along the left and right side surfaces of the automobile in the front-rear direction (the vehicle length direction, the y-axis direction shown in the figure) of the automobile. The floor cross members 14a to 14f extend in the left-right direction (vehicle width direction, x-axis direction shown in the figure) of the automobile. The z-axis direction shown in the figure is a direction orthogonal to both the x-axis and the y-axis, and indicates the height direction of the automobile (vehicle height direction). Each of the floor cross members 14a to 14f is joined to each of the left and right side sills 20 at both ends by welding, riveting, bolting or the like (hereinafter referred to as welding or the like).
[0022]
　Of the floor cross members 14a to 14f, the floor cross member 14a located on the frontmost side and the floor cross member 14f located on the rearmost side have the same thickness as the side sill 20 in the vertical direction.
[0023]
　The floor cross members 14b to 14e are arranged so as to extend in the vehicle width direction in the area surrounded by the left and right side sills 20, the floor cross member 14a, and the floor cross member 14f. As shown in FIG. 3, the floor cross members 14a and 14f, the floor cross members 14b to 14d, and the side sill 20 are arranged so that their upper surfaces are substantially the same. The lower surfaces of the floor cloth members 14b to 14e are arranged at the same position in the vertical direction, and are located above the lower surfaces of the floor cloth members 14a and 14f and the side sill 20.
[0024]
　Floor panels 12 are arranged under the floor cross members 14b to 14e. The floor panel 12 is fixed to the floor cross members 14a to 14f and the side sill 20 by welding or the like.
[0025]
　The floor cross members 14a to 14f may be made of a hat material (cross-section hat-shaped member), or the flange of the hat material may be joined to the floor panel 12. Further, the floor cross members 14a to 14f may be made of a hollow tubular member, or may have a rectangular cross section orthogonal to the longitudinal direction.
[0026]
　Two front side members 16a and 16b extend in the vehicle length direction inside the side sill 20 in the vehicle width direction. As shown in FIG. 2, the rear end portions of the front side members 16a and 16b may be in contact with the floor cross member 14f and may be fixed to the floor cross member 14f by welding or the like.
[0027]
　As shown in FIG. 3, the vertical position of the lower surface of the front side member 16b may coincide with the position of the lower surface of the floor cross members 14a and 14f, and may be above the lower surface by the thickness of the undercover 18. It may be located in. Further, the vertical position of the lower surface of the front side member 16b may be the same as the position of the lower surface of the side sill 20, or may be located above the lower surface by the thickness of the undercover 18. The vertical position of the lower surface of the front side member 16a may coincide with the position of the lower surface of the front side member 16b.
[0028]
　The upper surfaces of the front side members 16a and 16b may be in contact with the floor panel 12, or may be fixed to the floor panel 12 by welding or the like.
[0029]
　As shown in FIG. 2, at the position where the front side members 16a and 16b and the floor cross member 14a intersect, the floor cross member 14a may be provided with a groove-shaped retracting portion 14a'. At the position where the front side members 16a and 16b and the floor cross member 14a intersect, the front side members 16a and 16b may be inserted into these retracting portions 14a'and are joined to the floor cross member 14a by welding or the like. You may be. The front bumper 15 may be fixed to the front end of the front side members 16a and 16b.
[0030]
　Two rear side members 17a and 17b extend in the vehicle length direction behind the floor cross member 14f. The front ends of the rear side members 17a and 17b may be fixed to the floor cloth member 14f by welding or the like. The rear bumper 19 may be fixed to the rear end portions of the rear side members 17a and 17b. Further, a cross member 17c that connects the rear side member 17a and the rear side member 17b may be arranged in the middle of the rear side members 17a and 17b in the front-rear direction. The end portion of the cross member 17c may be fixed to each of the rear side member 17a and the rear side member 17b by welding or the like.
[0031]
　FIG. 4 is a schematic view showing a cross section along the alternate long and short dash line II-II'of FIG. As shown in FIG. 4, the floor panel 12 is arranged under the floor cross member 14c, and the front side members 16a and 16b are arranged under the floor panel 12. The front side members 16a and 16b are joined to the floor panel 12 by welding or the like.
[0032]
　As shown in FIG. 4, the side sill 20 has a hollow cross section perpendicular to the longitudinal direction. Inside the side sill 20, an energy absorbing member 22 is arranged so as to correspond to the positions of the floor cross members 14a to 14f in the vertical direction. The energy absorbing member 22 is made of, for example, an extruded aluminum material or a steel structure, and when the energy absorbing member 22 is an extruded aluminum material, the extrusion direction thereof coincides with the longitudinal direction of the floor cloth members 14a to 14f. It may be in the direction of
[0033]
　FIG. 5 is a schematic view showing a cross section along the alternate long and short dash line III-III'. The structure of the cross section shown in FIG. 5 is the same as that of FIG. 4 except that the floor cross member 14c does not exist.
[0034]
　As shown in FIGS. 4 and 5, the area inside the side sill 20 and below the floor panel 12 is the area where the battery 50 is mounted. The undercover 18 covers the lower side of the battery 50 and is fixed to the lower surface of the front side members 16a and 16b or the lower surface of the side sill 20.
[0035]
　As described above, the side sill 20, the floor cross members 14a to 14f, the front side members 16a and 16b, and the floor panel 12 constitute the basic structure of the vehicle body floor 110. The rear side members 17a and 17b, the front bumper 15, the undercover 18, the rear bumper 19, and the like may be attached to this basic structure.
[0036]
　Next, in the automobile lower structure 100 according to the present embodiment, a structure in which the automobile battery 50 is spread under the vehicle body floor 110 will be described. The battery 50 is attached to the lower side of the vehicle body floor 110 and is suspended from the vehicle body floor 110.
[0037]
　First, the battery 500 according to the present embodiment will be described. The battery 50 according to this embodiment is a battery cell or a battery module. A battery pack for a vehicle that houses a plurality of battery modules and has collision resistance is not included in the battery 50 in this embodiment. The battery pack may be referred to as a battery box, a battery case, an IPU case, a battery housing, or the like, but all of them have a structure having collision resistance.
[0038]
　A battery cell is a unit cell in which a common electrolyte is contained in one housing (case), and a battery module is an aggregate in which a plurality of battery cells are bundled. As the electrolyte contained in the battery cell, a liquid or solid electrolyte is used.
[0039]
　Explaining the difference between the battery module and the battery pack in detail, the battery pack includes, for example, a structure (such as a skeleton) for increasing rigidity for the purpose of improving collision resistance, or a component for increasing the rigidity. On the other hand, the battery module does not have a structure for increasing the rigidity or a component for increasing the rigidity. The battery module may have a frame-shaped component for connecting a plurality of battery cells, but this component is for connecting a plurality of battery cells and increases the rigidity of the battery module itself. It's not a thing.
[0040]
　Further, the battery pack has a box structure that seals the internal battery module, and the inside of the battery pack is airtight. On the other hand, the battery module does not have a structure for sealing the battery cell, and the battery cell may be partially exposed to the outside.
[0041]
　Further, the battery pack is equipped with a battery ECU (Electronic Control Unit) for controlling charging / discharging, but the battery module is not equipped with the battery ECU.
[0042]
　The battery 50 according to this embodiment does not have a structure or a component for increasing rigidity like a battery pack. Further, when the battery 50 is a battery module, the battery module does not have a structure for sealing the battery cell and does not have a battery ECU. Therefore, the battery 50 according to the present embodiment does not correspond to a so-called battery pack.
[0043]
　The above differences are due to the fact that the battery pack for a vehicle is configured in consideration of collision resistance and in consideration of maintainability such as replacement. On the other hand, the battery 50 according to the present embodiment is provided with a high-rigidity member such as a battery pack in order to consolidate the load paths at the time of collision into one system and efficiently transmit the load at the time of collision as described later. do not have.
[0044]
　As shown in FIG. 2, a plurality of batteries 50 are arranged on the vehicle body floor 110. The battery 50 is arranged in an area surrounded by the left and right side sills 20, the floor cross member 14a, and the floor cross member 14f, and is spread over almost the entire surface except for the area where the front side members 16a and 16b are arranged. You may.
[0045]
　As shown in FIGS. 3 to 5, the upper surface of the battery 50 is in contact with the lower surface of the floor panel 12 and is fixed to the floor panel 12. On the other hand, as shown in FIG. 4, the battery 50 may be fixed to the floor cross members 14a to 14f at the positions corresponding to the floor cross members 14a to 14f in the front-rear direction. As a fixing method, if there is a need for battery replacement / maintenance, removable fastening mechanisms such as bolt fastening, thumb turn clamper fastening, and fitting fastening can be used, and battery replacement / maintenance is required. If there is almost no property, rivet fastening, welding, adhesion, etc. can be used.
[0046]
　In an automobile such as an electric vehicle, it is desirable that a larger number of batteries 50 can be mounted in order to extend the cruising range. In the present embodiment, since the battery 50 is spread over the entire surface of the floor panel 12 under the vehicle body floor 110, more batteries 50 can be mounted. In particular, the battery 50 is also mounted between the front side members 16a and 16b and the side sill 20 outside the front side members 16a and 16b. Therefore, the amount of the battery 50 mounted can be increased, and the cruising range of the automobile can be made longer.
[0047]
　When the battery 50 is mounted on an automobile, the battery 50 is relatively heavy. Therefore, if the battery 50 is mounted at a high position in the vertical direction, the center of gravity of the automobile becomes high and the steering stability is impaired. In the present embodiment, the battery 50 is fixed to the lower side of the vehicle body floor 110. Therefore, the position of the center of gravity of the automobile is lowered, and the steering stability is improved.
[0048]
　Further, according to the present embodiment, since the battery 50 is directly fixed to the vehicle body floor 110 on the lower side and suspended from the vehicle body floor 110, parts such as a battery box that supports the battery 50 from the lower side are unnecessary. Become. As a result, the number of parts is reduced and the manufacturing cost is reduced. Further, since the load applied when the automobile collides is concentrated on the floor cross members 14a to 14f, the load path of the load is concentrated and the design is simplified, so that the design process can be reduced.
[0049]
　FIG. 6 is a schematic view showing an enlarged vicinity of the side sill 20 in FIG. FIG. 6 shows an example in which the floor cross member 14c is composed of a square pipe. As shown in FIG. 6, the floor panel 12 may be bent upward in an L-shaped cross section at a position adjacent to the side sill 20, and is inserted between the end of the floor cross member 14c and the side sill 20. May be good. The side sill 20, the floor panel 12, and the floor cross member 14c may be joined and integrated by welding or the like with the floor panel 12 inserted between the side sill 20 and the floor cross member 14c. The same applies to the joint portion between the other floor cross members 14b, 14d, 14e and the side sill 20. The undercover 18 may be fixed to the front side members 16a and 16b by tightening the bolts 72 to the front side members 16a and 16b. Further, the undercover 18 may be fixed to the side sill 20 by tightening the bolt 74 to the side sill 20.
[0050]
　The battery 50 may be fixed to the floor panel 12 or the floor cross member 14c by bolts 70. Specifically, the battery 50 may be provided with a bolt insertion hole 52 into which the bolt 70 is inserted. Further, the floor panel 12 or the floor cross member 14 may be provided with screw holes into which bolts 70 are tightened. In the battery 50, the bolt 70 is inserted into the bolt insertion hole 52 from the lower side, and the bolt 70 is tightened into the screw hole of the floor panel 12 or the floor cross member 14c, whereby the bolt 70 is tightened with respect to the floor panel 12 or the floor cross member 14c. It may be fixed.
[0051]
　Although FIG. 6 shows a cross section at the position of the floor cross member 14c, the battery 50 is fixed at the positions of the other floor cross members 14b, 14d, 14e as in FIG.
[0052]
　FIG. 7 is a schematic view showing an enlarged vicinity of the side sill 20 in FIG. At the position of the cross section shown in FIG. 5, there is no floor cross member above the battery 50. Therefore, the battery 50 may be fixed to the floor panel 12 by bolts 70. The floor panel 12 may be provided with screw holes into which bolts 70 are tightened. The battery 50 may be fixed to the floor panel 12 by inserting the bolt 70 into the bolt insertion hole 52 from below and tightening the bolt 70 into the screw hole of the floor panel 12.
[0053]
　If the floor panel 12 or the floor cloth members 14b to 14e are thin, screw holes are provided in the floor panel 12 or the floor cloth member 14 instead of providing screw holes in the floor panel 12 or the floor cloth members 14b to 14e. The nut to be held may be fixed by welding or the like. In this case, the bolt 70 for fixing the battery 50 is tightened to the nut fixed to the floor panel 12 or the floor cross member 14, and the battery 50 is fixed. In this embodiment, since the battery box described later can be omitted, the vehicle weight does not increase even if the thickness of the floor panel 12 and the floor cross members 14b to 14e is increased by the amount that the battery box is omitted. .. Therefore, the floor panel 12 and the floor cross members 14b to 14e can be made thick enough to form screw holes.
[0054]
　When a traveling vehicle collides with another vehicle, a ground-fixed object, or the like, the battery 50 is suddenly decelerated, and the load (inertial force) generated by the deceleration is applied to the battery 50. Alternatively, when another vehicle collides with a stopped vehicle, the battery 50 is suddenly accelerated, and the load (inertial force) generated by the acceleration is applied to the battery 50. In any case, even if the generated load (inertial force) is applied to the battery 50, according to the above configuration, the side sill 20 and the front side members 16a and 16b extending in the front-rear direction extend in the left-right direction. The vehicle body floor 110 has high rigidity due to the floor cross members 14a to 14f. In particular, the floor cross members 14a to 14f increase the rigidity against a collision from the side surface, and the front side members 16a and 16b increase the rigidity against a collision from the front surface. Since the battery 50 is directly fixed to the high-rigidity vehicle body floor 110, the load (inertial force) during deceleration or acceleration is directly transmitted to the high-rigidity vehicle body floor 110. In particular, when the upper surface of the battery 50 is fixed in contact with the lower surface of the floor panel 12, the frictional force generated between the upper surface of the battery 50 and the lower surface of the floor panel 12 and / or the bolt used for fixing the frictional force. Due to the shearing force of the detachable fastening mechanism (when the detachable fastening mechanism is not used, the rivet, the welded portion or the bonded portion), the load during deceleration or acceleration is applied to the vehicle body floor 110 having high rigidity. It is transmitted directly and reliably. This enhances the support function of the battery 50.
[0055]
　FIG. 8 is an enlarged view showing the vicinity of the side sill 20, and is a schematic view showing an example in which the water cooling panel 40 is arranged between the battery 50 and the floor panel 12. FIG. 8 shows a cross section of the floor cross member 14c along the extending direction, as in FIG. The water-cooled panel 40 is composed of, for example, a hollow structure of a rectangular cuboid, and a cooling liquid circulates inside. The battery 50 may be fixed to the floor panel 12 or the floor cross member 14 by bolts 70 with the water cooling panel 40 interposed between the battery 50 and the floor panel 12.
[0056]
　FIG. 9 is a perspective view showing a state in which the battery 50 and the water cooling panel 40 are viewed from below. As shown in FIG. 9, the battery 50 is provided with a bolt insertion hole 52 into which a bolt 70 is inserted. Further, the water cooling panel 40 may be provided with a bolt insertion hole 42 into which the bolt 70 is inserted.
[0057]
　The battery 50 and the water cooling panel 40 are so-called co-tightened by inserting bolts 70 into the bolt insertion holes 52 and 42 from below and tightening the bolts 70 into the screw holes of the floor panel 12 or the floor cross members 14b to 14e. May be fixed to the floor panel 12 or the floor cross members 14b to 14e.
[0058]
　When the battery 50 is a battery cell, a bolt insertion hole 52 is provided in the housing of the battery cell containing the electrolyte, and the bolt 70 is tightened into the screw hole of the floor panel 12 or the floor cross members 14b to 14e to cause the battery cell. Is fixed to the floor panel 12 or the floor cross members 14b-14e. Further, even when the battery 50 is a battery module, a bolt insertion hole 52 is provided in the housing of the battery cell, and the bolt 70 is tightened into the screw holes of the floor panel 12 or the floor cross members 14b to 14e to tighten the battery module. May be fixed to the floor panel 12 or the floor cross members 14b-14e.
[0059]
　When the battery 50 is a battery module, a bolt insertion hole 52 is provided in a frame-shaped component that bundles the battery cells, and the bolt 70 is tightened into the screw holes of the floor panel 12 or the floor cross members 14b to 14e. The battery module may be fixed to the floor panel 12 or the floor cross members 14b-14e. Further, in this case, the individual battery cells may be fixed to the top plate of a frame-shaped component that connects the battery cells to each other.
[0060]
　The electrodes of the battery 50 may be provided on the upper surface, the lower surface, or the side surface of the battery 50. When the electrodes are provided on the upper surface of the battery 50, relief processing or the like is appropriately performed on the floor panel 12 or the floor cross members 14b to 14e to avoid interference with the electrodes.
[0061]
　The battery 50 supplies electric power to an automobile by discharging it. Further, the battery 50 stores electric power generated by a motor generator included in the automobile or electric power supplied from the outside. The battery 50 generates heat in the process of discharging or charging. The heat generated by the heat generated by the battery 50 moves upward in the battery 50. Therefore, by arranging the water cooling panel 40 on the upper part of the battery 50, the battery 50 can be effectively cooled. This makes it possible to further extend the life of the battery 50.
[0062]
　In particular, when the battery 50 is rapidly charged, the amount of heat generated by the battery 50 increases. By arranging the water cooling panel 40 on the battery 50, it is possible to reliably suppress the temperature rise of the battery 50 even during rapid charging.
[0063]
　Next, based on FIGS. 10 to 12, the state in which the load path when the load (inertial force) is transmitted at the time of collision is aggregated by the lower structure 100 of the present embodiment will be described. In FIG. 10, in the configuration shown in FIG. 8, when the side surface (side sill 20) of the automobile collides with the pole 60 which looks like a utility pole, the direction in which the load is applied is indicated by a white arrow.
[0064]
　FIG. 10 shows a side collision (side collision) of an automobile, in which the vehicle body floor 110 moves from right to left in the figure, and the side sill 20 of the vehicle body floor 110 collides with the pole 60.
[0065]
　When the side sill 20 collides with the pole 60, sudden deceleration occurs in automobile components (for example, a seat fixed to the floor panel 12) including the vehicle body floor 110 moving from right to left in the figure, resulting in deceleration. The load (inertial force) generated by the above is transmitted in the direction indicated by the white arrow in FIG. The load applied to the battery 50 due to the deceleration of the battery 50 is transmitted to the floor cross members 14b to 14e via the bolt 70 and the floor panel 12. Since the floor cross members 14b to 14e are fixed to the side sill 20, the load transmitted to the floor cross members 14b to 14e is transmitted to the side sill 20. Then, the energy absorbing member 22 built in the side sill 20 absorbs the load.
[0066]
　FIG. 11 is a plan view showing a state in which the vehicle body floor 110 is viewed from above FIG. 10. In FIG. 11, the floor panel 12 is not shown. On the plan view shown in FIG. 11, the load due to the collision is transmitted to the floor cross members 14b, 14c, 14d and transmitted to the side sill 20 as shown by the white arrows.
[0067]
　As described above, the energy absorbing member 22 is made of an extruded aluminum material or the like, and is arranged in the side sill 20 so that the extrusion direction coincides with the longitudinal direction of the floor cross members 14a to 14f. As an example, the energy absorbing member 22 has a hollow structure, and the shape of the cross section orthogonal to the longitudinal direction is rectangular. Therefore, when the side sill 20 collides with the pole 60, the energy absorbing member 22 is crushed and the energy of the collision is absorbed.
[0068]
　As described above, according to the present embodiment, the load generated by the sudden deceleration of the battery 50 at the time of a collision is transmitted from the floor cross member 14 to the side sill 20. Therefore, on the cross-sectional view shown in FIG. 10, there is only one path (load path) through which the load is transmitted.
[0069]
　FIG. 12 shows an enlarged view of the vicinity of the side sill 20 in the structure of the comparative example in which the battery 50 is placed and fixed in the battery box 80 and the battery box 80 is fixed to the floor panel 12 for comparison with FIG. It is a schematic diagram.
[0070]
　In the structure shown in FIG. 12, the battery 50 is placed and fixed on the lower surface of the battery box 80. The battery box 80 has a complicated structure from the viewpoint of supporting the weight of the battery 50 and collision safety.
[0071]
　The battery box 80 has a highly rigid structure in order to withstand the load due to a collision. The battery box 80 has a cross member 82 for reinforcing rigidity from the bottom surface to the side surface of the battery box 80. The cross member 82 is arranged so as to extend in the same direction as the floor cross member, and is composed of another member having a hollow structure, ribs, and the like. The reason for providing such a cross member 82 is that if the cross member 82 is not provided, the battery box 80 may be deformed or the battery box 80 may be deformed together with the battery 50 when a load is applied to the battery 50 due to a collision. This is because there is a possibility of leaving the floor.
[0072]
　Therefore, in the structure shown in FIG. 12, the battery box 80 has a structure having high rigidity equivalent to that of the vehicle body floor. In such a structure, when the side sill 20 collides with the pole 60, there are two routes (load paths) through which the load is transmitted on the cross-sectional view shown in FIG. That is, when the side sill 20 collides with the pole 60, a sudden deceleration occurs in the components of the automobile including the vehicle body floor 110 moving from right to left in the figure, and the load generated by the deceleration is applied to the floor cross members 14b to. Along the longitudinal direction of 14e, it is transmitted in the direction indicated by the white arrow in FIG.
[0073]
　Further, the load applied to the battery 50 due to the deceleration of the battery 50 is transmitted to the cross member 82 provided from the bottom surface to the side surface of the battery box 80, and is transmitted to the floor cross members 14b to 14e. Therefore, the load applied to the battery 50 due to the deceleration of the battery 50 is transmitted in the direction indicated by the black arrow in FIG.
[0074]
　As described above, in the structure shown in FIG. 12, since there are two load paths, a load path indicated by a white arrow and a load path indicated by a black arrow, both load paths have rigidity that can withstand the load at the time of collision. It is necessary to secure it. In other words, in the structure shown in FIG. 12, both the floor cross member and the battery box have overlapping functions, and the functions are wasted.
[0075]
　For example, when the battery box 80 and the floor cross member are made of steel, in the structure shown in FIG. 12, the amount of the structural material used is increased in order to secure the required rigidity in both the battery box 80 and the floor cross member. It will increase and lead to an increase in the weight of the car.
[0076]
　On the other hand, according to the present embodiment, the load paths are aggregated into only one system indicated by the white arrow in FIG. This road path is the main path through which the load that stops the vehicle when it collides with the pole 60 is transmitted, and the rigidity of the vehicle body floor 110 is increased by members such as floor cross members 14a to 14f and front side members 16a and 16b. The above route. Since the load due to the deceleration of the battery 50 is directly transmitted to the strong vehicle body floor 110, the battery box 80 as in the structure shown in FIG. 12 is unnecessary. Here, the side collision of the automobile has been described as an example, but even when the automobile collides from the front, the load is transmitted in the longitudinal direction of the front side members 16a and 16b, so that the road paths are integrated into one. ..
[0077]
　Therefore, in the present embodiment, the vehicle body floor 110 only needs to have the required rigidity, and the battery box itself becomes unnecessary. As a result, the structure for transmitting the load in the battery box 80 can be abolished, and the structure for transmitting the load of the battery 50 in the event of a collision can be integrated into the strong vehicle body floor 110.
[0078]
　In particular, when high-strength steel is used to reduce the thickness of the steel material to reduce the weight, the members such as the floor cross member elastically buckle without plastic deformation due to the load at the time of collision. In order to delay the elastic buckling at the time of collision as much as possible and enhance the impact absorption capacity, it is advantageous that the cross-sectional area of ​​the cross section in the direction orthogonal to the longitudinal direction of these cross members is small and the plate thickness is thick. By consolidating the load paths divided into two as shown in FIG. 12 into one as shown in FIG. 10, the cross-sectional area of ​​the cross section is made smaller and the plate thickness is increased without increasing the total weight. Can be thickened. Therefore, according to the present embodiment, it is possible to increase the impact absorption capacity by delaying the elastic buckling at the time of collision as compared with the structure as shown in FIG. 12, and the amount of structural material used is reduced. It is possible to achieve weight reduction and reduce manufacturing costs.
[0079]
　Further, according to the present embodiment, as shown in FIG. 2, since the battery 50 is fixed over the entire surface of the vehicle body floor 110, there may be an effect of reducing the transmitted sound rate-determined by the mass. In other words, the heavier the weight of the lower structure 100, the less the transmitted sound from the outside of the vehicle. Therefore, it is not necessary to provide a separate member such as an asphalt sheet in order to reduce the transmitted sound, and by reducing these separate members, it is possible to reduce the weight.
Example
[0080] [0080]
　In the following, the results of comparing the load-bearing performance of the example in which the load paths are integrated into one as shown in FIG. 10 and the load-bearing performance of the comparative example in which the load paths are divided into two as shown in FIG. 12 will be described. FIG. 13 is a side view showing the hollow member 90 used when comparing the load bearing performance. Further, FIG. 14 is a schematic view showing a cross section along the alternate long and short dash line IV-IV'in FIG. 13. The hollow member 90 corresponds to the floor cloth member 14c shown in FIGS. 10 and 12.
[0081]
　In this comparison of load bearing performance, a hollow member 90 having a length in the longitudinal direction of 250 mm, a rectangular cross section shown in FIG. 14 having a long side of 80 mm and a short side of 40 mm was used. Then, as shown in FIG. 13, the hollow member 90 is arranged so that the longitudinal direction is the gravity direction, one end surface in the longitudinal direction is brought into contact with the floor 92, and a flat plate-shaped impactor is provided with respect to the other end surface. When a load was applied downward in the direction of gravity at a speed of 10 mm / s at 94, the load-bearing performance was compared by calculating the weight efficiency of the load-bearing capacity of the hollow member 90 with respect to the displacement of the impactor 94.
[0082]
　In the example in which the load paths were integrated into one, one hollow member 90 made of a steel plate having a yield strength of 1470 MPa class and a plate thickness of 2.0 mm was used. On the other hand, in the comparative example in which the load path is divided into two, two hollow members 90 made of a steel plate having a yield strength of 1470 MPa class and a plate thickness of 1.0 mm were used in parallel.
[0083]
　FIG. 15 is a characteristic diagram showing a comparison result of the load bearing performance of the example and the comparative example. In FIG. 15, the horizontal axis shows the displacement of the impactor 94. Further, in FIG. 15, F * on the vertical axis is a value indicating the load capacity in terms of weight efficiency, and is an Example or a comparative example with respect to the comparative example (maximum load applied to the hollow member 90 / member weight of the hollow member 90). The ratio of (load applied to the hollow member 90 / member weight of the hollow member 90) is shown. As shown in FIG. 15, the embodiment in which the load paths are integrated into one and the plate thickness of the hollow member 90 is increased has a load capacity as compared with the comparative example in which the load paths are divided into two and the plate thickness is reduced. It can be seen that both performance and weight reduction can be achieved at a high level.
[0084]
　As described above, according to the present embodiment, the battery 50 is directly fixed to the lower side with respect to the vehicle body floor 110 without using the battery box 80, so that the case where the battery box 80 is used is compared with the case where the battery box 80 is used. The number of load paths can be reduced. As a result, it is possible to achieve both load bearing performance and weight reduction.
Code description
[0085]
　12 Floor panel
　14a-14f Floor cross member
　15 Front bumper
　16a, 16b Front side member
　17a, 17b Rear side member
　17c Cross member
　18 Undercover
　19 Rear bumper
　20 Side sill
　22 Energy absorbing member
　40 Water cooling panel 42 , 52
　Bolt insertion hole
　50 Battery
　60 pole
　70,72,74 Bolt
　90 Hollow member
　92 Floor
　94 Impactor
The scope of the claims
[Claim 1]
　An automobile substructure 　including a vehicle body floor constituting an automobile floor and
　a battery cell or a battery module directly suspended and fixed from the vehicle body floor below the vehicle body floor .
[Claim 2]
　The lower structure of an automobile according to claim 1, wherein the battery cell or the battery module is fixed to the vehicle body floor in a state where the upper surface is in contact with the lower surface of the vehicle body floor.
[Claim 3]
　The first aspect of the present invention , wherein the battery cell or the battery module is further provided with a cooling panel through which a coolant circulates, and the
　battery cell or the battery module is fixed to the vehicle body floor with the cooling panel interposed between the battery cell or the battery module. Automotive substructure.
[Claim 4]
　The substructure of an automobile according to claim 3, wherein the upper surface of the battery cell or the battery module is in contact with the lower surface of the cooling panel.
[Claim 5]
　The vehicle body floor has a floor panel constituting the floor surface of an automobile, and the
　battery cell or the battery module is fixed to the floor panel, according to any one of claims 1 to 4. Automotive substructure.
[Claim 6]
　The vehicle body floor is arranged on the floor panel and has a cross member extending in the left-right direction of the automobile, and the
　battery cell or the battery module is fixed to the floor panel or the cross member. , The substructure of the automobile according to claim 5.
[Claim 7]
　The vehicle body floor has a side sill extending in the front-rear direction of the automobile at the outermost side in the left-right direction of the automobile, the
　floor panel is provided between the left and right side sill, and the
　battery cell or the battery module is a battery cell or a battery module. The substructure of an automobile according to claim 5 or 6, which is arranged over the entire area of ​​the floor panel including an area adjacent to the side sill.