JP7517519B2 - Vehicle underbody structure - Google Patents

Description

The present invention relates to a vehicle undercarriage.

The following Patent Document 1 discloses technology relating to a vehicle undercarriage structure that supports a battery unit, which is one of the driving force supply devices, on the vehicle underside of the floor panel. More specifically, in this prior art, a square cylindrical battery side frame is placed between the locker and the battery unit, and is attached adjacent to the locker and the battery unit.

On the other hand, when an impact load is input to the rocker due to a side collision of the vehicle and the rocker deforms toward the inside of the vehicle width direction (the inside of the rocker), a tensile force acts on the inside of the rocker in the vehicle width direction. In the above prior art, as mentioned above, the battery side frame is provided adjacent to the rocker, so a compressive force acts on the rocker side of the battery side frame.

In other words, in the above prior art, the tensile and compressive forces acting on adjacent parts of the rocker and battery side frame cancel each other out. This prevents the rocker and battery side frame from deforming, and prevents the rocker from intruding inward in the vehicle width direction (so-called inward folding).

JP 2013-133046 A

However, if a large load is applied locally to the rocker, such as in a pole side impact, there is a possibility that the rocker may break inward.

Taking the above facts into consideration, the present invention aims to provide a vehicle undercarriage structure that can more effectively absorb impact energy and suppress inward bending of the rocker.

The vehicle undercarriage structure of the present invention described in claim 1 is provided with a pair of rockers arranged on both outer sides of the vehicle width direction of the vehicle floor panel and extending along the vehicle fore-and-aft direction, the pair of rockers being arranged outer than the floor panel in the vehicle width direction and including an upper rocker portion forming an upper closed cross-sectional portion, a lower rocker portion being arranged on the vehicle lower side of the upper rocker portion and forming a lower closed cross-sectional portion, and a first impact absorbing portion consisting of a rectangular continuum arranged along the vehicle width direction within the lower closed cross-sectional portion, a storage battery being arranged on the vehicle lower side of the floor panel, and the first impact absorbing portion being arranged in a position overlapping with the storage battery when viewed from the side of the vehicle .

In the vehicle underbody structure according to the present invention, a rocker is disposed on each of both outer sides of a floor panel of a vehicle in a vehicle width direction, and each rocker extends along a front-rear direction of the vehicle. Here, the rocker includes an upper rocker portion that is disposed on the outer side of the floor panel in the vehicle width direction and forms an upper closed cross-sectional portion, and a lower rocker portion that is disposed on the vehicle lower side of the upper rocker portion and forms a lower closed cross-sectional portion.

Furthermore, a first shock absorbing portion composed of a rectangular continuum arranged along the vehicle width direction is provided in the lower closed cross-sectional portion of the rocker lower part . Therefore, part of the impact load input to the rocker during a side collision of the vehicle (hereinafter referred to as "vehicle side collision") is transmitted to the inside in the vehicle width direction via the first shock absorbing portion.

In general, the rigidity of the inside of the rocker in the vehicle width direction is high from the viewpoint of protecting the passenger compartment. Therefore, when a load is transmitted to the inside of the vehicle width direction through the first impact absorbing part, a reaction force is obtained against the rocker. This causes the first impact absorbing part to plastically deform, absorbing the impact energy.

Generally, a storage battery installed in a vehicle is designed to have high rigidity. For this reason, in the present invention , the storage battery is disposed on the vehicle lower side of the floor panel, and the first impact absorbing portion is disposed in a position overlapping with the storage battery in a side view of the vehicle. As a result, part of the impact load input to the rocker during a side collision of the vehicle is transmitted to the storage battery via the first impact absorbing portion.

As mentioned above, the storage battery is designed to have high rigidity, so when an impact load is input to the storage battery, a reaction force is obtained from the storage battery. This causes the first impact absorbing section to plastically deform, absorbing the impact energy. In other words, it is possible to reduce the impact load even with a short stroke.

In addition, the impact load transmitted to the storage battery via the first impact absorbing part of the rocker can be prevented from intruding inward in the vehicle width direction (so-called inward bending) by obtaining a reaction force from the storage battery.

Note that examples of "storage batteries" include lithium ion batteries, nickel-metal hydride batteries, and silicon batteries. In addition, "storage battery" here refers to, for example, a state in which multiple battery modules are housed in a case (hereinafter referred to as a "battery pack").

The vehicle underbody structure of the present invention as described in claim 2 is a vehicle underbody structure of the present invention as described in claim 1 , in which a floor cross member is spanned along the vehicle width direction between the pair of rockers on the floor panel, and a second impact absorbing portion is provided in the upper closed cross-sectional portion spanned in the vehicle width direction at a position overlapping with the floor cross member when viewed from the side of the vehicle.

In the vehicle underbody structure according to the present invention, the floor cross member is bridged between the pair of rockers on the floor panel in the vehicle width direction, while the second impact absorbing portion is bridged in the vehicle width direction at a position overlapping with the floor cross member in the vehicle side view at the upper closed cross section of the rocker.

In other words, the first shock absorbing portion and the second shock absorbing portion are arranged in the vehicle width direction within the closed cross-sectional portion of the rocker. The first shock absorbing portion is arranged at a position overlapping with the storage battery in a side view of the vehicle, and the second shock absorbing portion is arranged at a position overlapping with the floor cross member in a side view of the vehicle.

Therefore, in the event of a side collision of the vehicle, part of the impact load input to the rocker is transmitted to the storage battery via the first impact absorbing section, and is also transmitted to the floor cross member via the second impact absorbing section. When an impact load is input to the storage battery, a reaction force is obtained from the storage battery, and when an impact load is input to the floor cross member, a reaction force is obtained from the floor cross member (strictly speaking, from the rocker on the opposite side to the rocker to which the impact load was input, via the floor cross member). This causes the first impact absorbing section and the second impact absorbing section to plastically deform, absorbing the impact energy.

In addition, in the event of a side collision of the vehicle, a load transfer path can be formed that transfers the load to the battery side via the first impact absorbing part of the rocker, and a load transfer path that transfers the load to the floor cross member side via the second impact absorbing part of the rocker. Therefore, it is possible to distribute the impact load input to the rocker.

In other words, in the present invention, a first impact absorbing section and a second impact absorbing section are provided within the closed cross-sectional portion of the rocker, and the first impact absorbing section and the second impact absorbing section are positioned so as to overlap the storage battery and the floor cross member, respectively, when viewed from the side of the vehicle, and the reaction forces from the storage battery and the floor cross member are utilized to prevent the rocker from bending inward.

As described above, the vehicle underbody structure according to the present invention as set forth in claim 1 has the excellent effect of effectively absorbing impact energy and suppressing inward bending of the rocker.

The vehicle underbody structure according to the present invention described in claim 2 has the excellent effect of obtaining a reaction force from the storage battery, plastically deforming the first impact member, and absorbing impact energy.

The vehicle underbody structure of the present invention described in claim 2 has the excellent effect of being able to obtain a reaction force from the storage battery and also from the floor cross member, thereby plastically deforming the first impact member and the second impact member to absorb impact energy.

1 is a plan view of a vehicle underside to which a vehicle underside structure relating to a first embodiment is applied. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1. 5A and 5B are schematic diagrams showing, in a time series, a state in which an impact load is input to a rocker of a vehicle to which the vehicle underbody structure relating to the first embodiment is applied. 5C and 5D are schematic diagrams showing, in a time series, a state in which an impact load is input to a rocker of a vehicle to which the vehicle underbody structure relating to the first embodiment is applied. 13A and 13B are schematic diagrams illustrating, in a comparative example, a state in which an impact load is input to a rocker of a vehicle in a time series manner. 13C and 13D are schematic diagrams illustrating, in a comparative example, a state in which an impact load is input to a rocker of a vehicle in a time series. 3 is a cross-sectional view corresponding to FIG. 2 and showing a modified example of the vehicle underbody structure relating to the first embodiment. FIG. FIG. 3 is a cross-sectional view corresponding to FIG. 2 and showing a vehicle underbody structure relating to a second embodiment. FIG. 4 is a cross-sectional view corresponding to FIG. 2 and showing a first modified example of the vehicle underbody structure relating to the second embodiment. FIG. 11 is a cross-sectional view corresponding to FIG. 2 and showing a second modified example of the vehicle underbody structure relating to the second embodiment.

The vehicle undercarriage structure according to an embodiment of the present invention will be described with reference to the drawings. Note that the arrows FR, UP, and RH shown in each drawing indicate the forward, upward, and rightward directions of a vehicle to which the vehicle floor structure according to an embodiment of the present invention is applied, respectively. In the following description, when the directions of front-rear, up-down, and left-right are simply used, they refer to front-rear in the front-rear direction of the vehicle, up-down in the up-down direction of the vehicle, and left-right when facing forward, unless otherwise specified.

First Embodiment
(Configuration of vehicle underbody structure)

First, the configuration of the vehicle underbody structure according to this embodiment will be described. FIG. 1 shows a plan view of the vehicle underbody 10 to which the vehicle underbody structure according to this embodiment is applied, and FIG. 2 shows a cross-sectional view taken along line 2-2 in FIG. 1.

As shown in FIG. 1, a floor panel 12 extends along the vehicle width direction and the vehicle front-rear direction in the vehicle underside 10. The floor panel 12 has bead portions 12A that protrude intermittently along the vehicle front-rear direction, and multiple bead portions 12A are arranged along the vehicle width direction. The formation of these bead portions 12A improves the rigidity of the floor panel 12 itself.

In addition, rockers 14, 16 extend along the vehicle front-rear direction on both ends of the floor panel 12 in the vehicle width direction, and a floor cross member (hereinafter simply referred to as "cross member") 18 is bridged on the floor panel 12 between the rockers 14 and 16 along the vehicle width direction. The cross member 18 is disposed between the bead portions 12A that are disposed along the vehicle front-rear direction.

As shown in FIG. 2, a battery pack (rechargeable battery) 20 is provided below the floor panel 12 as a driving force supply device for supplying power to a power unit such as a motor.

As mentioned above, rockers 14, 16 extend along the vehicle front-rear direction at both ends of the floor panel 12 in the vehicle width direction. The rockers 14, 16 are described below. Note that rocker 16 has substantially the same configuration as rocker 14, so a description of it will be omitted.

As shown in FIG. 2, in this embodiment, the rocker 14 includes an outer portion 22 located on the outside in the vehicle width direction, and an inner portion 24 located on the inside in the vehicle width direction. The rocker 14 is formed from a metal such as an aluminum alloy, and the outer portion 22 and the inner portion 24 are integrally formed by extrusion or drawing, and the outer portion 22 and the inner portion 24 form a closed cross-sectional portion 26.

The outer portion 22 is configured to include an outer wall portion 22A formed in the up-down direction in a cross section cut along the vehicle width direction, an inclined upper wall portion 22B provided on the upper side of the outer wall portion 22A and inclined upward as it approaches the inside of the vehicle width direction, and an inclined lower wall portion 22C provided on the lower side of the outer wall portion 22A and inclined downward as it approaches the inside of the vehicle width direction.

On the other hand, the inner portion 24, in a cross-sectional shape cut along the vehicle width direction, is configured to include an upper inner wall portion 24A formed along the up-down direction at the upper side of the inner portion 24, and a lower inner wall portion 24B formed along the vehicle up-down direction at the lower side of the inner portion 24. This lower inner wall portion 24B is located inside the upper inner wall portion 24A in the vehicle width direction, and a lateral wall portion 24C formed along a substantially horizontal direction is provided between the lower inner wall portion 24B and the upper inner wall portion 24A. Therefore, the lateral wall portion 24C is formed so as to be connected to the lower inner wall portion 24B and the upper inner wall portion 24A.

In addition, an inclined upper wall portion 24D is provided above the upper inner wall portion 24A, which inclines upward as it approaches the outside in the vehicle width direction, and this inclined upper wall portion 24D is formed so as to connect to the inclined upper wall portion 22B of the outer portion 22. A flange portion 28 extends upward from a top portion 27 where the inclined upper wall portion 24D of the inner portion 24 and the inclined upper wall portion 22B of the outer portion 22 are connected. The lower end portion of a pillar (not shown) is connected to this flange portion 28.

A bottom wall portion 24E is provided below the lower inner wall portion 24B, extending generally horizontally toward the outside in the vehicle width direction, and is formed so as to connect to the inclined lower wall portion 22C of the outer portion 22. A fastener 32 can be inserted into the bottom wall portion 24E, and the fixing piece 30 provided on the battery pack 20 can be fastened to the locker 14 via the fastener 32.

As described above, the upper inner wall portion 24A of the inner portion 24 is located outside the lower inner wall portion 24B in the vehicle width direction. This causes the area of the closed cross-sectional portion to differ between the upper portion (rocker upper portion) 14A and the lower portion (rocker lower portion) 14B of the rocker 14. In other words, the area of the lower closed cross-sectional portion 34 provided on the lower portion 14B side of the rocker 14 is larger than the area of the upper closed cross-sectional portion 36 provided on the upper portion 14A side of the rocker 14, and the rigidity is set to be higher on the lower portion 14B side of the rocker 14 than on the upper portion 14A side of the rocker 14.

A ladder-shaped shock absorbing section (second shock absorbing section) 38 is provided in the upper closed cross-sectional section 36 of the rocker 14, and the shock absorbing section 38 is arranged so as to overlap with the cross member 18 in a side view of the vehicle. A ladder-shaped shock absorbing section (first shock absorbing section) 40 is formed in the lower closed cross-sectional section 34 of the rocker 14, and the shock absorbing section 40 is arranged so as to overlap with the battery pack 20 in a side view of the vehicle.

Here, the shock absorbing portions 38 and 40 will be described.
The shock absorbing parts 38, 40 are integrally formed with the outer part 22 and the inner part 24. The shock absorbing part 38 has an upper wall 38A that spans between the upper inner wall part 24A of the inner part 24 and the outer wall part 22A of the outer part 22 in a substantially horizontal direction (vehicle width direction). A lower wall 38B is formed below the upper wall 38A so as to face the upper wall 38A, and the lower wall 38B is connected to the lateral wall part 24C to separate the upper part 14A and the lower part 14B of the rocker 14. The upper wall 38A and the lower wall 38B are spanned in the vertical direction by a plurality of (here, two) connecting walls 38C.

On the other hand, the shock absorbing section 40 has an upper wall 40A that spans between the lower inner wall 24B of the inner section 24 and the outer wall 22A of the outer section 22 in a substantially horizontal direction (vehicle width direction). A lower wall 40B is formed below the upper wall 40A so as to face the upper wall 40A, and the upper wall 40A and the lower wall 40B are spanned in the vertical direction by multiple (here, three) connecting walls 40C.

(Action and Effect of Vehicle Underbody Structure)
Next, the operation and effects of the vehicle underbody structure according to the present embodiment will be described.

As shown in FIG. 2, in this embodiment, the outer portion 22 and the inner portion 24 of the rocker 14 are integrally formed, and the outer portion 22 and the inner portion 24 form a closed cross-sectional portion 26.

As a result, for example, although not shown, the strength of the rocker can be increased compared to when it is formed by joining two panels, an outer part and an inner part, to each other. Also, when joining the two panels, the outer part and the inner part, welding, fastening, etc. are required, but in this embodiment, the outer part 22 and the inner part 24 are formed as a single unit, so these processes are not necessary, and the cost can be reduced accordingly.

Furthermore, in this embodiment, in the upper portion 14A (in the upper closed cross-sectional portion 36) of the rocker 14, an impact absorbing portion 38 is bridged in the vehicle width direction between the outer portion 22 and the inner portion 24 at a position overlapping with the cross member 18 in the vehicle side view. In addition, in the lower portion 14B (in the lower closed cross-sectional portion 34) of the rocker 14, an impact absorbing portion 40 is bridged in the vehicle width direction between the outer portion 22 and the inner portion 24 at a position overlapping with the battery pack 20 in the vehicle side view.

Therefore, when an impact load F is input to the rocker 14 during a side collision of the vehicle, part of the impact load F is transmitted to the cross member 18 via the impact absorbing portion 38 provided on the upper portion 14A side of the rocker 14 (transmitted load F1), and is transmitted to the battery pack 20 via the impact absorbing portion 40 provided on the lower portion 14B side of the rocker 14 (transmitted load F2).

When an impact load (transmitted load F1) is transmitted to the cross member 18 via the impact absorbing section 38, the rocker 14 receives a reaction force N1 from the cross member 18 (or, more precisely, the rocker 16 (see FIG. 1) on the opposite side of the rocker 14 to which the impact load F is input via the cross member 18). When an impact load (transmitted load F2) is transmitted to the battery pack 20 via the impact absorbing section 40, the rocker 14 receives a reaction force N2 from the battery pack 20. As a result, the impact absorbing sections 38 and 40 each undergo plastic deformation, absorbing the impact energy.

Here, for example, as shown in Figures 5(A), (B) and 6(C) and (D), when the shock absorbing part is provided as a shock absorbing member 100 separately from the rocker 102, when the shock absorbing member 100 is disposed within the closed cross-sectional portion 104 of the rocker 102, it is necessary to provide a rib 106 for restricting movement within the closed cross-sectional portion 104 to prevent the shock absorbing member 100 from shifting position due to impact.

In this way, if a movement-restricting rib 106 is provided within the closed cross-sectional portion 104 of the rocker 102, when an impact load F is input to the rocker 102 and the impact absorbing member 100 undergoes plastic deformation, the plastic deformation of the impact absorbing member 100 may be hindered by the rib 106, as shown in Figures 6(C) and (D).

When the plastic deformation of the shock absorbing member 100 is inhibited in this way, a so-called uncrushed portion is generated (uncrushed portion 108), and the amount of shock energy absorbed by the rocker 102 is reduced by the amount of the uncrushed portion. In other words, there is a possibility that the shock energy cannot be absorbed efficiently.

In contrast, in this embodiment, as shown in Figures 3(A), (B) and 4(C), (D), the shock absorbing portion 40 is integrally formed with the outer portion 22 and the inner portion 24, so there is no need to provide ribs or the like, as shown in Figure 5(A). Therefore, in this embodiment, it is possible to prevent the shock absorbing portion 40 from remaining uncrushed, as shown in Figures 4(C) and (D).

In other words, it is possible to effectively absorb the impact energy due to the collision load F, and therefore it is possible to suppress the inward bending of the rocker 14 even if a large load is input locally to the rocker 14, such as in a pole side collision. In other words, in this embodiment, by suppressing the remaining crushing of the impact absorbing section 40, it is possible to more effectively absorb the impact energy and suppress the inward bending of the rocker 14.

In this embodiment, as shown in FIG. 2, the shock absorbing parts 38, 40 are provided within the closed cross-sectional portion 26 of the rocker 14. On the other hand, in FIG. 3 and FIG. 4, only the shock absorbing part 40 is provided within the closed cross-sectional portion 26 of the rocker 14, but this is to match the configurations in FIG. 5 and FIG. 6 shown as comparative examples, and since the same can be said about the shock absorbing parts 38, 40 in this embodiment, they are not shown.

In the present embodiment shown in FIG. 2, as described above, when an impact load F is input to the rocker 14 during a side collision of the vehicle, part of the impact load F is transmitted to the cross member 18 via the impact absorbing portion 38 provided on the upper portion 14A side of the rocker 14 (transmitted load F1), and is transmitted to the battery pack 20 via the impact absorbing portion 40 provided on the lower portion 14B side of the rocker 14 (transmitted load F2).

In other words, here, a load transfer path A is formed that transfers the load to the cross member 18 side via the impact absorbing portion 38 of the rocker 14, and a load transfer path B is formed that transfers the load to the battery pack 20 side via the impact absorbing portion 40 of the rocker 14. This makes it possible to distribute the load when an impact load F is input to the rocker 14, and also makes it possible to change the ratio of the load burden between the upper portion 14A of the rocker 14 and the lower portion 14B of the rocker 14.

This reduces the impact load F2 transmitted to the battery pack 20 disposed below the floor panel 12. As a result, for example, the rigidity of the battery pack 20 itself can be reduced by the amount of the reduction in the impact load F2 transmitted to the battery pack 20. In this case, the plate thickness of the battery pack 20 can be reduced, thereby reducing the weight of the battery pack 20. In addition, the reduced plate thickness of the battery pack 20 allows the amount of battery modules 20A accommodated in the battery pack 20 to be increased.

(Supplementary information regarding this embodiment)
In this embodiment, the shock absorbing parts 38 and 40 are each formed in a ladder shape, but the shapes of the shock absorbing parts 38 and 40 are not limited to this. For example, the shapes can be appropriately changed in relation to the plate thickness, such as by reducing the plate thickness and forming a honeycomb shape. Furthermore, the plate thicknesses of the shock absorbing parts 38 and 40 may be different, and the shock absorbing parts 38 and 40 do not necessarily have to have the same shape.

In addition, in this embodiment, the impact absorbing portion 38 is provided in the rocker 14 at a position overlapping the cross member 18 in a side view of the vehicle, and the impact absorbing portion 40 is provided in a position overlapping the battery pack 20 in a side view of the vehicle, but the embodiments applicable to the present invention are not limited to this.

For example, as shown in FIG. 7, some vehicles do not have a cross member 18 (see FIG. 2) on the floor panel 12. In this case, no impact absorbing portion is provided on the upper portion 42A of the rocker 42, which overlaps with the cross member 18 (see FIG. 2) in a side view of the vehicle. Therefore, an impact absorbing portion (first impact absorbing portion) 40 is provided on the lower portion 42B of the rocker 42, but when an impact load F is input to the rocker 14 during a side collision of the vehicle, part of the impact load F is transmitted to the battery pack 20 via the impact absorbing portion 40 (transmitted load F3).

When an impact load (transmitted load F3) is transmitted to the battery pack 20 via the impact absorbing section 40, the rocker 14 receives a reaction force N3 from the battery pack 20. This causes the impact absorbing section 40 to plastically deform, so that even in this case, the impact energy is absorbed.

Second Embodiment
In the above first embodiment, a case was described in which the battery pack 20 (see FIG. 2) was used as a driving force supply device for supplying electric power to the power unit, but in this embodiment, as shown in FIG. 8, a case will be described in which a hydrogen tank 44, which is a fuel cell, is used as a driving force supply device. Note that a description of the configuration that is substantially the same as in the first embodiment will be omitted. The embodiments applied to the present invention are not limited to this.

In addition, in the event of a side collision of the vehicle, the impact load input to the rocker is transmitted to the floor cross member arranged on the floor panel, so if a fuel cell is arranged on the vehicle lower side of the floor panel, it is preferable because this prevents the impact load from being input to the fuel cell.

As shown in FIG. 8, in this embodiment, the impact absorbing portion 38 is provided in the locker 46 at a position that does not overlap with the hydrogen tank 44 in a side view of the vehicle (on the upper portion 46A side of the locker 46).

In this case, when an impact load F is input to the rocker 46 during a side collision of the vehicle, part of the impact load F is transmitted to the cross member 18 via the impact absorbing portion 38 provided on the upper portion 46A side of the rocker 46 (transmitted load F4). Then, when the impact load (transmitted load F4) is transmitted to the cross member 18 via the impact absorbing portion 38, the rocker 46 obtains a reaction force N4 from the cross member 18. As a result, the impact absorbing portion 38 undergoes plastic deformation, and the impact energy is absorbed.

In other words, it is possible to reduce the impact load F even with a short stroke, and to prevent the rocker 46 from intruding inward in the vehicle width direction. In this embodiment, it is also possible to prevent the impact load F from being input to the hydrogen tank 44 disposed below the floor panel 12.

(Supplementary information regarding this embodiment)
In the above embodiment, as shown in FIG. 1, the cross member 18 is bridged between the rockers 14, 16. However, for example, as shown in FIG. 9, if the hydrogen tank 47 has a large diameter, the hydrogen tank 47 may be arranged along the fore-and-aft direction of the vehicle below a tunnel portion 50 that protrudes along the fore-and-aft direction of the vehicle from the center of the floor panel 48 in the vehicle width direction.

In this case, the cross member 52 is spanned between a pair of rockers 54 arranged at both ends of the floor panel 48 in the vehicle width direction, with the tunnel section 50 between them. Here, the cross member 52 is formed to conform to the shape of the tunnel section 50, but this is not limited to this.

For example, although not shown, the cross member may be divided by a tunnel section and two cross members may be provided along the vehicle width direction. In this case, however, one longitudinal end of the cross member is connected to the rocker and the other longitudinal end of the cross member is connected to the tunnel section. Therefore, the impact load transmitted from the rocker to the cross member receives a reaction force from the tunnel section.

In the above embodiment, a vehicle using a battery pack 20 (see FIG. 2) and a hydrogen tank 44 (see FIG. 8) as a driving force supply device has been described, but this embodiment can also be applied to a gasoline vehicle.

In the case of a gasoline-powered vehicle, for example, as shown in FIG. 10, since there is no need to arrange a driving force supply device below the floor panel 56, the position of the floor panel 56 in the vertical direction can be set low. Therefore, the impact absorbing section (first impact absorbing section) 60, which is arranged so as to overlap the cross member 58 arranged above the floor panel 56 in a side view of the vehicle, is provided on the lower portion 62A side of the rocker 62.

Although one example of an embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above, and one embodiment and various modified examples may be used in appropriate combination, and the present invention may of course be embodied in various forms without departing from the spirit of the present invention.

10. Vehicle underside (vehicle underside structure)
12 Floor panel 14 Rocker
14A Upper part (upper part of locker)
14B Lower part (Locker lower part)
16 Rocker 18 Cross member (floor cross member)
20 Battery pack (storage battery)
26 Closed cross section
34 Lower closed section
36 Upper closed section
38 Impact absorbing portion (second impact absorbing portion, rocker)
40 Impact absorbing portion (first impact absorbing portion, rocker)
42 Rocker 46 Rocker 48 Floor panel 52 Cross member 54 Rocker 56 Floor panel 58 Cross member (floor cross member)
60 Impact absorbing portion (first impact absorbing portion)
62 Rocca

Claims (2)

A pair of rockers are disposed on both outer sides of a floor panel of a vehicle in a width direction of the vehicle and extend along a front-rear direction of the vehicle.
a rocker upper portion that is disposed on the outer side of the floor panel in a vehicle width direction and that forms an upper closed cross-sectional portion;
A rocker lower portion provided on a vehicle lower side of the rocker upper portion and forming a lower closed cross-sectional portion;
a first impact absorbing portion configured as a rectangular continuum arranged along a vehicle width direction within the lower closed cross-sectional portion;
Including,
A vehicle underbody structure , wherein a storage battery is disposed below the floor panel, and the first impact absorbing portion is disposed in a position overlapping with the storage battery in a side view of the vehicle . A floor cross member is disposed between the pair of rockers on the floor panel along the vehicle width direction,
The vehicle underbody structure according to claim 1 , wherein the upper closed cross-sectional portion is provided with a second impact absorbing portion that is bridged in a vehicle width direction at a position that overlaps with the floor cross member in a vehicle side view .