Vehicle underbody structure

Abstract

In a vehicle underbody structure that includes a component made of a dilatant material to protect the battery pack, the cost increase is suppressed. [Solution] The vehicle underbody structure S comprises a battery pack 20 mounted under the vehicle floor and a shear panel 30 positioned below the battery pack 20. The vehicle underbody structure S further comprises an impact protection member 40 made of a dilatant material, positioned between the lower surface of the battery pack 20 and the shear panel 30. The impact protection member 40 made of a dilatant material is positioned only between the lower surface of the battery pack 20 and the shear panel 30.

Description

Technical Field

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[0001] The present disclosure relates to a vehicle underfloor structure.

Background Art

[0002] In the vehicle underfloor structure disclosed in Patent Document 1, the case of the battery pack has a double structure. The inner layer of the case is formed of metal or resin, and the outer layer of the case is formed of a dilatancy material. A member formed of a dilatancy material protects the battery pack.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure aims to suppress an increase in cost in a vehicle underfloor structure including a member formed of a dilatancy material that protects a battery pack.

Means for Solving the Problems

[0005] The vehicle underfloor structure according to the first aspect includes a battery pack mounted under the vehicle floor, a shared panel disposed below the battery pack, and a shock protection member formed of a dilatancy material disposed only between the lower surface of the battery pack and the shared panel.

[0006] In this aspect, the vehicle underfloor structure includes a battery pack mounted under the vehicle floor and a shared panel disposed below the battery pack. Therefore, the shared panel can protect the battery pack from falling objects on the road, speed breakers, bottoming roads, and the like.

[0007] By the way, in order to properly protect the battery pack, the shear panel presents problems such as increased weight and cost. Also, in order to properly absorb impact energy, it becomes necessary to provide a vertical gap (shock absorption stroke) between the battery pack and the shear panel. Therefore, in this embodiment, the underbody structure of the vehicle further includes an impact protection member formed of a dilatant material and positioned between the lower surface of the battery pack and the shear panel. Therefore, the impact protection member formed from a dilatant material functions to protect the battery pack from impacts from below the floor. In particular, because dilatant materials have the property of becoming rigid under high input, a small impact absorption stroke is required. As a result, the occurrence of the above-mentioned problems related to the share panel can be suppressed.

[0008] Furthermore, in this embodiment, the impact protection member, which is made of a dilatant material, is positioned only between the bottom surface of the battery pack and the shear panel. In other words, it is not positioned on the top or side of the battery pack, where the possibility of contact with falling objects is low. Therefore, it is possible to suppress the cost increase that would result from providing impact protection members made of dilatant materials.

[0009] In the second embodiment of the vehicle underbody structure, the shear panel is made of fiber-reinforced plastic, as in the first embodiment.

[0010] In this embodiment, the share panel is made of fiber-reinforced plastic. Therefore, compared to shear panels made of steel, it is easier to reduce the weight of the structure. Fiber-reinforced plastic shear panels are highly effective at preventing penetration by sharp foreign objects, but they are not good at absorbing impact. However, impact absorption can be handled by impact protection members made of dilatant materials.

[0011] In the embodiments described later, the shear panel comprises a shear panel body and a reinforcing member, both of which are made of fiber-reinforced plastic. However, the shear panel of this embodiment is not limited to this. In the shear panel of this embodiment, it is sufficient that at least the shear panel body is made of fiber-reinforced plastic. Furthermore, the shear panel of this embodiment may consist only of the shear panel body.

[0012] In the third embodiment of the vehicle underbody structure, in the first or second embodiment, the share panel comprises a share panel body, and the impact protection member fills the space between the share panel body and the lower surface of the battery pack without any gaps.

[0013] In this embodiment, the share panel comprises a share panel body. The impact protection member fills the space between the share panel body and the bottom surface of the battery pack without any gaps. Therefore, the battery pack can be protected more effectively. In addition, the structure can be made smaller in the vertical direction of the vehicle compared to when the above-mentioned gap is provided.

[0014] The vehicle underbody structure according to the fourth embodiment is such that, in any of the first to third embodiments, the battery pack comprises a lower case having a bottom plate, the bottom plate having a bulge that partially bulges upward, and the impact protection member is partially provided in the portion of the bottom plate corresponding to the portion where the bulge is located.

[0015] In this embodiment, the battery pack comprises a lower case having a bottom plate, and the bottom plate has a bulge that partially protrudes upward. Therefore, the rigidity of the base plate can be improved. Furthermore, in this embodiment, the impact protection member is partially provided in the portion of the bottom plate corresponding to the area where the bulging portion is located. Therefore, it is possible to reduce the amount of impact protection material made of dilatant material while ensuring protection of the battery pack.

[0016] In the vehicle floor structure according to the fifth aspect, in any of the first to fourth aspects, the shock protection member is integrated with the battery pack or the shared panel.

[0017] In this aspect, the shock protection member is integrated with the battery pack or the shared panel. Therefore, in the vehicle assembly process, the shock protection member can be handled integrally with either the battery pack or the shared panel.

Advantages of the Invention

[0018] As described above, according to the present disclosure, in a vehicle floor structure including a member formed of a dilatancy material that protects a battery pack, an increase in cost can be suppressed.

Brief Description of the Drawings

[0019] [Figure 1] It is a diagram showing a vehicle having a vehicle floor structure according to an embodiment. [Figure 2] It is a schematic cross-sectional view showing an enlarged structure where a shock protection member is arranged. [Figure 3] It is a cross-sectional view corresponding to FIG. 2 according to a modified example.

Modes for Carrying Out the Invention

[0020] Hereinafter, the vehicle floor structure S according to the embodiment will be described.

[0021] Note that the arrow FR appropriately shown in each figure indicates the front of the vehicle, the arrow UP indicates the upper side of the vehicle, and the arrow LH indicates the left side in the vehicle width direction, respectively. Also, when the front-back, up-down, and left-right directions are used without special mention in the following description, they indicate the front-back in the vehicle front-back direction, the up-down in the vehicle up-down direction, and the left-right in the vehicle width direction.

[0022] FIG. 1 is a diagram showing a vehicle 10 having a vehicle floor structure S.

[0023] As shown in Figure 1, the underbody structure S of the vehicle comprises a battery pack 20 mounted under the vehicle floor, a shear panel 30 positioned below the battery pack 20, and an impact protection member 40 made of a dilatant material positioned between the lower surface of the battery pack 20 and the shear panel 30.

[0024] The battery pack 20 includes a battery case 22. The battery case 22 includes, for example, a lower case and an upper case. Multiple battery modules 24 are housed inside the battery case 22.

[0025] The lower case 26 has a bottom plate portion 26A. The bottom plate portion 26A has a bulge portion 26A1 that partially bulges upward and extends in the longitudinal direction of the vehicle. The battery module 24 is positioned on top of the bulge portion 26A1.

[0026] The impact protection member 40, formed from a dilatant material, is a component that absorbs and mitigates impact by utilizing the dilatancy effect. Dilatancy refers to the property of certain fluids or materials to instantly increase in viscosity and harden when subjected to a sudden external force (pressure or impact). Dilatant materials are normally soft and easily deformable, but have the characteristic of temporarily hardening when an impact is applied. Dilatant materials can be made of, for example, plastics, rubber, or resin materials woven with fibers that contain an organic substance that imparts dilatancy properties. The organic substance that imparts dilatancy properties is, for example, liquid or gel-like. The impact protection member 40, formed from a dilatant material, is, for example, made of a bag filled with a liquid or gel-like substance that imparts dilatancy properties. Examples of gel-like substances include thermally conductive silicone grease, specifically, materials containing a silicone polymer with at least one thermally conductive material such as aluminum, silver, copper, nickel, zinc oxide, alumina, magnesium oxide, aluminum nitride, boron nitride, silicon nitride, diamond, graphite, carbon nanotubes, metallic silicon, carbon fiber, or fullerene.

[0027] The impact protection member 40, which is made of a dilatant material, is positioned only between the bottom surface of the battery pack 20 and the shear panel 30. In other words, it is not positioned on the top or sides of the battery pack 20.

[0028] The share panel 30 may be made of iron, but as an example, it is made of fiber-reinforced plastic. The share panel 30 comprises a share panel body 31 and a share panel reinforcing member (not shown). The impact protection member 40 fills the gap between the share panel body 31 and the bottom surface of the battery pack 20 without any gaps. However, the impact protection member 40 may be attached to the lower surface of the battery pack 20 while maintaining a distance from the share panel body 31. Alternatively, the impact protection member 40 may be attached to the share panel 30 while maintaining a distance from the lower surface of the battery pack 20.

[0029] (modified version) Figure 3 is a cross-sectional view relating to a modified example.

[0030] As shown in Figure 4, in the modified example, the impact protection member 40 is partially provided in the portion of the bottom plate portion 26A corresponding to the portion where the bulging portion 26A1 is located. Specifically, in the modified example, the impact protection member 40 is divided into multiple sections in the vehicle width direction. No members made of dilatant material are placed between the multiple impact protection members 40.

[0031] <Effects and Effects> Next, the effects and advantages of this embodiment will be described.

[0032] In this embodiment, the underbody structure S of the vehicle includes a battery pack 20 mounted under the vehicle floor and a share panel 30 positioned below the battery pack 20. Therefore, the shared panel 30 can protect the battery pack 20 from falling objects on the road, speed breakers, bottoming roads, etc.

[0033] By the way, in order to properly protect the battery pack 20, the shear panel 30 presents problems such as increased weight and increased cost. Also, in order to properly absorb impact energy, it becomes necessary to provide a vertical gap (shock-absorbing stroke) between the battery pack 20 and the shear panel 30. Therefore, in this embodiment, the underbody structure S of the vehicle further includes an impact protection member 40 made of a dilatant material, which is positioned between the lower surface of the battery pack 20 and the shear panel 30. Therefore, the impact protection member 40, formed from a dilatant material, functions to protect the battery pack 20 from impacts from below the floor. In particular, because the dilatant material has the property of becoming rigid under large inputs, a small stroke is required for impact absorption. As a result, the occurrence of the above-mentioned problems with the share panel 30 can be suppressed.

[0034] Furthermore, in this embodiment, the impact protection member 40, which is made of a dilatant material, is positioned only between the lower surface of the battery pack 20 and the shear panel 30. In other words, it is not positioned on the upper or side surfaces of the battery pack 20, where the possibility of contact with falling objects is low. Therefore, it is possible to suppress the cost increase that would result from providing the impact protection member 40 made of a dilatant material. In addition, the weight of the share panel 30 can be reduced.

[0035] Furthermore, in this embodiment, the share panel 30 is made of fiber-reinforced plastic. Therefore, compared to a configuration in which the shear panel 30 is made of iron, it is easier to reduce the weight of the structure. Although the shear panel 30 made of fiber-reinforced plastic has a high ability to prevent penetration by sharp foreign objects, it does not absorb impact well. However, impact absorption can be handled by the impact protection member 40 made of a dilatant material.

[0036] In this embodiment, the share panel 30 includes a share panel body 31. The impact protection member fills the space between the share panel body 31 and the lower surface of the battery pack 20 without any gaps. Therefore, the battery pack 20 can be protected more effectively. In addition, compared to the case where the above-mentioned gap is provided, the structure in the vertical direction of the vehicle can be made smaller. As a result, for example, the battery capacity can be increased or the passenger compartment can be made larger.

[0037] Furthermore, in this embodiment, the battery pack 20 includes a lower case 26 having a bottom plate portion 26A, and the bottom plate portion 26A has a bulging portion 26A1 that partially bulges upward. Therefore, the rigidity of the bottom plate portion 26A can be improved. Furthermore, in this embodiment, the impact protection member 40 is partially provided in the portion of the bottom plate portion 26A corresponding to the portion where the bulging portion 26A1 is located. Therefore, while ensuring protection of the battery pack 20, the amount of impact protection member 40 made of dilatant material used can be reduced.

[0038] Furthermore, in this embodiment, the impact protection member 40 may be integrated with the battery pack 20 or the shear panel 30. In this case, during the vehicle assembly process, the impact protection member 40 can be handled integrally with either the battery pack 20 or the shear panel 30. For example, the impact protection member 40 may be joined to the shear panel 30 with an adhesive or the like. In this case, the impact protection member 40 does not have to be joined to the battery pack 20.

[0039] While preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to those described above. [Explanation of Symbols]

[0040] 10. Vehicle (Underbody structure of the vehicle) 20 battery packs 26 Lower Cases 26A Bottom plate part 26A1 Bulge 30 Share Panels 31 Share Panel Main Unit 40 Impact protection components

Claims

1. The battery pack is mounted under the vehicle floor, A share panel located on the lower side of the aforementioned battery pack, An impact protection member made of a dilatant material is disposed only between the lower surface of the battery pack and the shear panel, Equipped with, Vehicle underbody structure.

2. The aforementioned shear panel is made of fiber-reinforced plastic. The underbody structure of a vehicle according to claim 1.

3. The aforementioned share panel comprises a share panel body, The impact protection member fills the gap between the share panel body and the lower surface of the battery pack without any gaps. The underbody structure of a vehicle according to claim 1 or claim 2.

4. The battery pack comprises a lower case having a bottom plate, The bottom plate portion has a bulge that partially protrudes upward, The impact protection member is partially provided in the bottom plate portion corresponding to the portion where the bulging portion is located. The underbody structure of a vehicle according to claim 1 or claim 2.

5. The impact protection member is integrated with the battery pack or the shear panel. The underbody structure of a vehicle according to claim 1 or claim 2.

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