Vehicle lower part structure

Abstract

To enhance sealability between a vehicle frame and a power storage device further.SOLUTION: In a vehicle lower part structure, a power storage device 20 is situated to a lower side of a vehicle frame 10. The power storage device 20 contains a power storage module 21, a peripheral wall part 22, a pair of reinforcement parts 23, and an upper wall part 24. The peripheral wall part 22 extends to form a ring-like shape so as to surround the power storage module 21 when viewed from a vertical direction. The pair of reinforcement parts 23 are provided on both sides of the peripheral wall part 22 in a vehicle longitudinal direction, respectively. The pair of reinforcement parts 23 are formed on one piece with the peripheral wall part 22. The upper wall part 24 is situated to upper sides of the peripheral wall par 22 and the reinforcement parts 23 so as to cover an upper direction of the power storage module 21. A seal member 30 seals a space between the vehicle frame 10 and the upper wall part 24. The seal member 30 is configured so as to extend to form a ring-like shape when viewed from the vertical direction and at the same time so that the whole of a portion situated outside the peripheral wall part 22 overlaps with the reinforcement parts 23.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Japanese Patent Application Laid-Open Publication No. 2020-142589 (Patent Document 1) discloses that a battery pack is disposed below a floor panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-142589 Summary of the Invention [Problem to be solved by the invention]

[0004] Vehicle power storage devices are expected to have ever-increasing energy capacities. For example, vehicles are expected in which part of the power storage device functions as the vehicle's floor panel. In such vehicles, water intrusion between the vehicle frame and the power storage device can be a problem. To address this issue, it is conceivable to dispose a seal member between the vehicle frame and the power storage device. However, there is still room for improvement in the sealing performance between the vehicle frame and the power storage device.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a vehicle underbody structure that can further improve the sealing performance between the vehicle frame and the electricity storage device. [Means for solving the problem]

[0006] A vehicle understructure according to an aspect of the present disclosure includes a vehicle frame, an electric storage device, and a sealing member. The electric storage device is located below the vehicle frame. The electric storage device includes an electric storage module, a peripheral wall portion, a pair of reinforcing portions, and an upper wall portion. The peripheral wall portion extends in a ring shape so as to surround the electric storage module when viewed from the top-bottom direction. The pair of reinforcing portions are provided on both sides of the peripheral wall portion in the left-right direction of the vehicle. The pair of reinforcing portions are formed integrally with the peripheral wall portion. The upper wall portion is located above the peripheral wall portion and the reinforcing portion so as to cover the upper side of the electric storage module. The sealing member seals between the vehicle frame and the upper wall portion. When viewed from the top-bottom direction, the sealing member extends in a ring shape and the entire portion located outside the peripheral wall portion overlaps with the reinforcing portion.

[0007] In the vehicle understructure according to an aspect of the present disclosure, the power storage module preferably includes a plurality of power storage cells, and the seal member overlaps the plurality of power storage cells when viewed from the top-bottom direction.

[0008] A vehicle understructure according to an aspect of the present disclosure preferably further includes an intermediate member. Each of the plurality of energy storage cells includes a cell case. The cell case includes a pressure release valve facing in one direction along the horizontal direction for releasing pressure inside the cell case. The intermediate member has higher flame resistance than the resin member included in the energy storage module. The intermediate member is disposed above the pressure release valve.

[0009] In a vehicle undercarriage structure according to an aspect of the present disclosure, in at least one of the plurality of energy storage cells, the pressure release valve preferably faces at least one side in the vehicle front-rear direction and is located radially outward of the ring-shaped seal member when viewed from the top-bottom direction, and the intermediate member is located radially outward of the ring-shaped seal member when viewed from the top-bottom direction.

[0010] A vehicle undercarriage structure according to an aspect of the present disclosure preferably further includes a second intermediate member. In at least one other of the plurality of energy storage cells, the pressure release valve faces at least one side in the vehicle longitudinal direction and is located radially inward of the ring-shaped sealing member when viewed from the top-bottom direction. The second intermediate member has higher flame resistance than the resin member included in the energy storage module. The second intermediate member is disposed above the pressure release valve. The second intermediate member is located radially inward of the ring-shaped sealing member when viewed from the top-bottom direction. [Effects of the Invention]

[0011] According to the present disclosure, the sealing performance between the vehicle frame and the power storage device can be further improved. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a side view showing a vehicle equipped with a vehicle undercarriage according to an embodiment of the present disclosure. [Figure 2] 1 is an exploded perspective view showing an electricity storage device according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a plan view showing the power storage device. [Figure 4] FIG. 2 is a plan view schematically showing the power storage device with some components removed. [Figure 5A] 4 is a cross-sectional view of the vehicle underbody structure when the power storage device of FIG. 3 is viewed from the direction of the arrows along the line VA-VA. [Figure 5B] 4 is a cross-sectional view of the vehicle undercarriage structure when the power storage device of FIG. 3 is viewed from the direction of the VB-VB line arrows. [Figure 6] FIG. 10 is a cross-sectional view of a vehicle underbody structure according to a modified example of the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a vehicle underbody structure according to each embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and description thereof will not be repeated.

[0014] In addition, the arrows F, B, U, D, L, and R in the figures used in the following explanation indicate directions based on the vehicle, with arrow F indicating "forward," arrow B indicating "backward," arrow U indicating "upward," arrow D indicating "downward," arrow L indicating "leftward," and arrow R indicating "rightward."

[0015] 1 is a side view showing a vehicle equipped with a vehicle undercarriage according to an embodiment of the present disclosure. A vehicle 1000 equipped with a vehicle undercarriage 1 according to this embodiment is, for example, an electric vehicle that can be driven by a motor, such as an electric vehicle or a hybrid vehicle. The vehicle 1000 includes a passenger compartment 2. The passenger compartment 2 is located above the vehicle undercarriage 1.

[0016] The vehicle 1000 may further include a floor carpet 3 and a cushioning member 4. The floor carpet 3 defines the vehicle interior 2. The cushioning member 4 is disposed below the floor carpet 3. The cushioning member 4 is lighter than metal and may be made of a material that is softer than metal. The cushioning member 4 is made of a material that includes, for example, foamed resin.

[0017] Fig. 2 is an exploded perspective view showing an electric storage device according to an embodiment of the present disclosure. Fig. 3 is a plan view showing the electric storage device. Fig. 4 is a plan view showing the electric storage device in a state where some components are removed. Fig. 5A is a cross-sectional view of a vehicle lower structure when the electric storage device of Fig. 3 is viewed from the direction of the arrows along line VA-VA. Fig. 5B is a cross-sectional view of a vehicle lower structure when the electric storage device of Fig. 3 is viewed from the direction of the arrows along line VB-VB.

[0018] As shown in Figures 2 to 5B, a vehicle undercarriage 1 according to one embodiment of the present disclosure includes a vehicle frame 10, an energy storage device 20, a sealing member 30, an intermediate member 40, a second intermediate member 50, and a third intermediate member 60.

[0019] The vehicle frame 10 includes a pair of side members 11, a front member 12, and a rear member 13. The vehicle frame 10 does not necessarily include a floor panel that defines the passenger compartment 2.

[0020] The pair of side members 11 extend in the front-to-rear direction of the vehicle (see FIG. 5A). The pair of side members 11 are located on either side of the center of the vehicle understructure 1 in the vehicle width direction. The pair of side members 11 include a left side member 11L and a right side member 11R. The left side member 11L is located on the left side of the center of the vehicle understructure 1 in the vehicle width direction. The right side member 11R is located on the right side of the center of the vehicle understructure 1 in the vehicle width direction.

[0021] The front member 12 extends in the vehicle width direction (see FIG. 5B) and connects the front portions of the pair of side members 11 together.

[0022] The rear member 13 extends in the vehicle width direction (see FIG. 5B) and connects the rear portions of the pair of side members 11 together.

[0023] As shown in FIGS. 1, 2, 5A and 5B, the power storage device 20 is located below the vehicle frame 10.

[0024] The electricity storage device 20 includes an electricity storage module 21, a peripheral wall portion 22, a pair of reinforcing portions 23, an upper wall portion 24, and a lower wall portion 25. For ease of explanation, Fig. 4 illustrates the electricity storage device 20 with the upper wall portion 24 removed.

[0025] The power storage module 21 includes a plurality of power storage cells 21A. The plurality of power storage cells 21A are arranged in the left-right direction. The plurality of power storage cells 21A are arranged in the front-rear direction.

[0026] Each of the plurality of storage cells 21A includes a cell case 21B. The cell case 21B houses an electrode assembly (not shown). The cell case 21B includes a pressure relief valve 21C facing in one direction along the horizontal direction for releasing pressure inside the cell case 21B (see FIGS. 2 and 4).

[0027] In at least one of the plurality of electric storage cells 21A, the pressure release valve 21C faces at least one side in the front-to-rear direction of the vehicle. In a group of electric storage cells 21A aligned in the left-to-right direction, electric storage cells 21A having pressure release valves 21C facing forward and electric storage cells 21A having pressure release valves 21C facing rearward are arranged alternately in the left-to-right direction. The electric storage module 21 includes two of the above-described groups of electric storage cells 21A. The two groups of electric storage cells 21A are aligned in the front-to-rear direction.

[0028] 2, 4, 5A, and 5B, the peripheral wall portion 22 extends in a rectangular ring shape so as to surround the electricity storage module 21 when viewed from above and below. The peripheral wall portion 22 includes a front wall portion 22A, a rear wall portion 22B, a left wall portion 22C, and a right wall portion 22D. The front wall portion 22A may be fixed to the front member 12 (see FIG. 5B). The rear wall portion 22B may be fixed to the rear member 13.

[0029] The pair of reinforcing portions 23 are provided on both sides in the vehicle left-right direction of the peripheral wall portion 22. The pair of reinforcing portions 23 are formed integrally with the peripheral wall portion 22.

[0030] The pair of reinforcing portions 23 includes a left front reinforcing portion 23A, a left rear reinforcing portion 23B, a left side side reinforcing portion 23C, a right front reinforcing portion 23D, a right rear reinforcing portion 23E, and a right side side reinforcing portion 23F.

[0031] The left front reinforcement portion 23A and the left rear reinforcement portion 23B extend from the left side of the peripheral wall portion 22. The left side reinforcement portion 23C is connected to the left front reinforcement portion 23A and the left rear reinforcement portion 23B. The left side reinforcement portion 23C is spaced apart from the peripheral wall portion 22. The left side reinforcement portion 23C may be fixed to the left side member 11L (see FIG. 5A).

[0032] The right front reinforcement portion 23D and the right rear reinforcement portion 23E extend from the right side of the peripheral wall portion 22. The right side reinforcement portion 23F is connected to the right front reinforcement portion 23D and the right rear reinforcement portion 23E. The right side reinforcement portion 23F is spaced apart from the peripheral wall portion 22. The right side reinforcement portion 23F may be fixed to the right side member 11R (see FIG. 5A).

[0033] Upper wall portion 24 is located above peripheral wall portion 22 and reinforcing portion 23 so as to cover the upper side of power storage module 21. Upper wall portion 24 may be in direct contact with peripheral wall portion 22 and reinforcing portion 23. Upper wall portion 24 may be made of, for example, carbon fiber reinforced plastics (CFRP).

[0034] The seal member 30 provides a seal between the vehicle frame 10 and the upper wall portion 24. The seal member 30 may be made of any elastically deformable material, such as a rubber-like resin material or a foamed resin.

[0035] In this embodiment, the entire sealing member 30 may extend horizontally, thereby suppressing variations in the sealing surface pressure of the sealing member 30. When viewed from the top-bottom direction, the sealing member 30 extends in a ring shape, and the entire portion of the sealing member 30 located outside the peripheral wall portion 22 overlaps with the reinforcing portion 23.

[0036] Furthermore, the sealing member 30 overlaps with the plurality of energy storage cells 21A when viewed from the top-bottom direction. In at least one of the plurality of energy storage cells 21A, the pressure release valve 21C is located on the outer side in the radial direction of the ring-shaped sealing member 30 when viewed from the top-bottom direction. In at least another of the plurality of energy storage cells 21A, the pressure release valve 21C is located on the inner side in the radial direction of the ring-shaped sealing member 30 when viewed from the top-bottom direction.

[0037] More specifically, some of the multiple pressure relief valves 21C are located forward of the seal member 30. Others of the multiple pressure relief valves 21C are located rearward of the seal member 30. Still others of the multiple pressure relief valves 21C are located radially inward of the seal member 30.

[0038] The intermediate member 40 (first intermediate member), the second intermediate member 50, and the third intermediate member 60 are made of a material containing a resin member that has higher flame resistance than the resin member contained in the energy storage module 21. Examples of the resin member contained in the energy storage module 21 include a separator or an insulating member (neither of which is shown) contained in the energy storage module 21.

[0039] An example of the evaluation of flame resistance is the UL standard (Underwriter's Laboratories: UL test number 94 standard). Materials that can be used to improve flame resistance include, for example, glass cloth, carbon cloth made of carbon fiber, fluorine fiber cloth made of fluorine fiber, and fluorine resin film. For example, a material with a resin material such as polybutylene terephthalate (PBT) as the base material to which a halogen compound, antimony oxide, glass fiber, or the like is added may be used.

[0040] The intermediate member 40, the second intermediate member 50, and the third intermediate member 60 are disposed above the pressure release valve 21C. The intermediate member 40 is located radially outward of the ring-shaped seal member 30 when viewed from the top-bottom direction. The intermediate member 40 is located rearward of the seal member 30, but may be located forward of the seal member 30. The second intermediate member 50 is located radially inward of the ring-shaped seal member 30 when viewed from the top-bottom direction. The third intermediate member 60 is located radially outward of the ring-shaped seal member 30 when viewed from the top-bottom direction. The third intermediate member 60 is located forward of the seal member 30, but may be located rearward of the seal member 30.

[0041] As described above, the vehicle understructure 1 according to one embodiment of the present disclosure includes the vehicle frame 10, the power storage device 20, and the seal member 30. The power storage device 20 is located below the vehicle frame 10. The power storage device 20 includes the power storage module 21, a peripheral wall portion 22, a pair of reinforcing portions 23, and an upper wall portion 24. The peripheral wall portion 22 extends in a ring shape so as to surround the power storage module 21 when viewed from the top-bottom direction. The pair of reinforcing portions 23 are provided on both sides of the peripheral wall portion 22 in the left-right direction of the vehicle. The pair of reinforcing portions 23 are formed integrally with the peripheral wall portion 22. The upper wall portion 24 is located above the peripheral wall portion 22 and the reinforcing portion 23 so as to cover the upper side of the power storage module 21. The seal member 30 seals between the vehicle frame 10 and the upper wall portion 24. When viewed from above and below, the sealing member 30 extends in a ring shape, and the entire portion positioned outside the peripheral wall portion 22 overlaps with the reinforcing portion 23.

[0042] Reinforcement portion 23 extending from peripheral wall portion 22 is highly rigid and relatively resistant to bending. Therefore, with the above configuration, in the portion of sealing member 30 that overlaps with reinforcing portion 23, sealing member 30 and upper wall portion 24 are firmly sandwiched between vehicle frame 10 and upper wall portion 24. This further improves the sealing performance provided by sealing member 30 between vehicle frame 10 and power storage device 20.

[0043] In one embodiment of the present disclosure, the energy storage module 21 includes a plurality of energy storage cells 21 A. The sealing member 30 overlaps the plurality of energy storage cells 21 A when viewed from the top and bottom.

[0044] According to the above configuration, the sealing performance of the seal member 30 is improved on both sides of the electricity storage module 21 in the left-right direction of the vehicle, and the proportion of the electricity storage module 21 occupied by the plurality of electricity storage cells 21A can be increased on the front and rear of the electricity storage module 21 in the vehicle direction. Consequently, the energy capacity of the electricity storage device 20 provided in the vehicle undercarriage 1 can be increased. Furthermore, because the curvature of the upper wall portion 24 located above the plurality of electricity storage cells 21A is suppressed, the sealing performance of the seal member 30 is also improved above the plurality of electricity storage cells 21A.

[0045] The vehicle undercarriage 1 according to an embodiment of the present disclosure further includes an intermediate member 40. Each of the plurality of energy storage cells 21A includes a cell case 21B. The cell case 21B includes a pressure release valve 21C facing in one direction along the horizontal direction for releasing pressure inside the cell case 21B. The intermediate member 40 has higher flame resistance than the resin member included in the energy storage module 21. The intermediate member 40 is disposed above the pressure release valve 21C.

[0046] According to the above configuration, even if the pressure release valve 21C opens in an emergency and a fire breaks out from the pressure release valve 21C, the intermediate member 40 can prevent the fire from spreading upward.

[0047] In one embodiment of the present disclosure, in at least one of the plurality of energy storage cells 21A, the pressure release valve 21C faces at least one side in the vehicle front-rear direction and is located radially outward of the ring-shaped seal member 30 when viewed from the top-bottom direction. The intermediate member 40 is located radially outward of the ring-shaped seal member 30 when viewed from the top-bottom direction.

[0048] According to the above configuration, even if a fire breaks out from the pressure release valve 21C in an emergency, the fire can be prevented from spreading inside the ring-shaped sealing member 30, and the fire can be further prevented from spreading toward the passenger compartment. Furthermore, the intermediate member 40 can also prevent the fire from spreading upward outside the ring-shaped sealing member 30.

[0049] The vehicle understructure 1 according to an embodiment of the present disclosure further includes a second intermediate member 50. In at least one other of the plurality of energy storage cells 21A, the pressure release valve 21C faces at least one side in the vehicle front-rear direction and is located radially inward of the ring-shaped sealing member 30 when viewed from the top-bottom direction. The second intermediate member 50 has higher flame resistance than the resin member included in the energy storage module 21. The second intermediate member 50 is disposed above the pressure release valve 21C. The second intermediate member 50 is located radially inward of the ring-shaped sealing member 30 when viewed from the top-bottom direction.

[0050] According to the above configuration, even if a fire breaks out from the pressure release valve 21C in an emergency, the second intermediate member 50 can prevent the fire from spreading upward inside the ring-shaped seal member 30.

[0051] The seal member 30 does not have to extend entirely horizontally. Fig. 6 is a cross-sectional view of a vehicle underbody structure according to a modified example of an embodiment of the present disclosure. Fig. 6 shows a cross-section corresponding to the cross-sectional view shown in Fig. 5A.

[0052] In the vehicle undercarriage structure 101 according to this modified example, the sealing member 130 extends from above the upper wall portion 24 to the fixed position between the left side member 11L and the left side side reinforcement portion 23C. The sealing member 130 extends from above the upper wall portion 24 to the fixed position between the right side member 11R and the right side side reinforcement portion 23F.

[0053] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0054] 1,101 vehicle undercarriage, 2 passenger compartment, 3 floor carpet, 4 shock absorber, 10 vehicle frame, 11 side member, 11L left side member, 11R right side member, 12 front member, 13 rear member, 20 power storage device, 21 power storage module, 21A power storage cell, 21B cell case, 21C pressure release valve, 22 peripheral wall portion, 22A front wall portion, 22B rear wall portion, 22C left wall portion, 22D right wall portion, 23 reinforcement portion, 23A left front reinforcement portion, 23B left rear reinforcement portion, 23C left side reinforcement portion, 23D right front reinforcement portion, 23E right rear reinforcement portion, 23F right side reinforcement portion, 24 upper wall portion, 25 lower wall portion, 30,130 sealing member, 40 intermediate member, 50 second intermediate member, 60 Third intermediate member, 1000 cars.

Claims

1. A vehicle frame; a power storage device; a sealing member; the power storage device is located below the vehicle frame, The power storage device is a power storage module; A peripheral wall portion; A pair of reinforcing parts; an upper wall portion; the peripheral wall portion extends in a ring shape so as to surround the power storage module when viewed from above and below, the pair of reinforcing portions are provided on both sides of the peripheral wall portion in the vehicle left-right direction and are formed integrally with the peripheral wall portion, the upper wall portion is located above the peripheral wall portion and the reinforcing portion so as to cover an upper portion of the power storage module, The sealing member seals between the vehicle frame and the upper wall portion, and when viewed from the top-bottom direction, extends in a ring shape, with the entire portion located outside the peripheral wall portion overlapping with the reinforcing portion.

2. the energy storage module includes a plurality of energy storage cells; The vehicle underbody structure according to claim 1 , wherein the sealing member overlaps the plurality of electric storage cells when viewed from the top-bottom direction.

3. Further comprising an intermediate member; Each of the plurality of storage cells includes a cell case; the cell case includes a pressure relief valve facing in one direction along the horizontal direction for relieving pressure inside the cell case; The vehicle underbody structure according to claim 2 , wherein the intermediate member has higher flame resistance than a resin member included in the electricity storage module, and is disposed above the pressure release valve.

4. the pressure release valve of at least one of the plurality of energy storage cells faces at least one side in a vehicle front-rear direction and is located radially outward of the ring-shaped seal member when viewed from the up-down direction, The vehicle underbody structure according to claim 3 , wherein the intermediate member is located radially outward of the ring-shaped seal member when viewed from the top-bottom direction.

5. Further comprising a second intermediate member; in at least another of the plurality of electric storage cells, the pressure release valve faces at least one side in a vehicle front-rear direction and is located radially inward of the ring-shaped seal member when viewed from the up-down direction, 5. The vehicle undercarriage structure according to claim 4, wherein the second intermediate member has higher flame resistance than the resin member included in the energy storage module, is disposed above the pressure release valve, and is positioned radially inward of the ring-shaped sealing member when viewed from the up-down direction.

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