Vehicle lower structure

Abstract

To quickly discharge liquid accumulated on a seal member.SOLUTION: The battery pack 10 is disposed between the pair of side members 32,32. The seal strip 20 is bridged between the side member 32 and the battery pack 10. Further, the seal strip 20 extends in an inclined manner along the vehicle front-rear direction in the vehicle side view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Disclosed herein is a vehicle undercarriage. [Background technology]

[0002] An electric vehicle (BEV) is equipped with a battery pack, which is placed, for example, under the floor of the vehicle interior.

[0003] For example, in Patent Document 1, rockers, which are framework members, are provided on both ends of the vehicle body, and the gap between the rockers and the battery pack is sealed with an elastic seal material.

[0004] In Patent Document 2, a sealing material is provided on the case of a battery pack. The sealing material is provided around the entire periphery of the top surface of the case. Furthermore, a water drainage portion is formed by removing a portion of the sealing material.

[0005] In Patent Document 3, the battery pack is supported by a frame. A cover member is disposed on the lower surfaces of the battery pack and the frame. A ring-shaped seal member is disposed between the upper surface of the cover member and the lower surface of the frame. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-14349 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-193290 [Patent Document 3] Japanese Patent Publication No. 2023-51652 Summary of the Invention [Problem to be solved by the invention]

[0007] This specification discloses a vehicle undercarriage structure that is capable of quickly draining liquid that has accumulated on a seal member. [Means for solving the problem]

[0008] This specification discloses a vehicle undercarriage structure. The structure includes a pair of side members, a battery pack, and a sealing strip. The pair of side members extend in the longitudinal direction of the vehicle. The pair of side members are also disposed at both ends of the vehicle interior in the transverse direction. The battery pack is disposed between the pair of side members. The sealing strip spans between the side members and the battery pack. The sealing strip also extends obliquely along the longitudinal direction of the vehicle when viewed from the side of the vehicle.

[0009] According to the above configuration, the liquid on the seal strip flows down the inclined seal strip and is discharged obliquely downward.

[0010] In the above configuration, the sealing strip may be inclined downward so as to become lower toward the rear in the vehicle longitudinal direction.

[0011] According to the above configuration, in a vehicle whose main movement is forward movement, the liquid on the seal strip is more likely to flow rearward.

[0012] In the above configuration, the rear ends of the pair of side members may be connected to a cross member. The cross member extends in the vehicle width direction. The cross member is a hollow member. Both ends of the cross member in the vehicle width direction are open. The rear end of the sealing strip abuts against the inner wall of the cross member. A discharge hole is provided in the inner wall of the cross member at the point of abutment with the rear end of the sealing strip.

[0013] According to the above configuration, the liquid is discharged from the seal strip to the outside of the vehicle via the cross member.

[0014] In the above configuration, a rear seal strip may be installed in the gap between the cross member and the rear end of the battery pack. The rear seal strip is installed so as to have an arched shape. That is, the rear seal strip has an apex at the center in the vehicle width direction and becomes lower as it goes outward in the vehicle width direction.

[0015] According to the above configuration, liquid that has entered the gap between the cross member and the rear end of the battery pack can be made to flow out to both ends in the vehicle width direction.

[0016] In the above configuration, the seal strip may have a U-shaped cross section.

[0017] According to the above configuration, the seal strip can be used as a gutter. [Effects of the Invention]

[0018] According to the vehicle undercarriage structure disclosed in this specification, liquid that has accumulated on the seal member can be quickly drained. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is an exploded perspective view illustrating an example of a vehicle interior structure. [Figure 2] FIG. 2 is a perspective view of the battery case alone. [Figure 3] FIG. 3 is a perspective view of the battery case alone, facing in the opposite direction to FIG. 2. [Figure 4] 2 is a cross-sectional view taken along the line AA in FIG. 1, illustrating the fastening structure of the battery case. FIG. [Figure 5] FIG. [Figure 6] FIG. 6 is a perspective view of the frame alone, facing in the opposite direction to FIG. 5. [Figure 7] FIG. 5 is a cross-sectional view showing a first modification (U-shaped seal) of FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1 to 7 show an example of a vehicle underbody structure according to this embodiment. The vehicle underbody structure according to this embodiment is mounted on an electric vehicle (BEV). The vehicle underbody structure according to this embodiment includes a battery pack 10, a sealing strip 20, and a frame 30.

[0021] In Figures 1 to 7, the front-to-rear direction of the vehicle is indicated by the FR axis. The width direction of the vehicle is indicated by the RW axis. The vertical direction is indicated by the UP axis. The positive direction of the FR axis is the front. The positive direction of the RW axis is the right direction. The positive direction of the UP axis is the height direction.

[0022] 1.Cabin structure FIG. 1 illustrates an exploded perspective view of vehicle components around the vehicle interior. A battery pack 10 is disposed under the floor of the vehicle interior. The battery pack 10 is supported by a frame 30. The frame 30 is a frame-shaped framework member. For example, the frame 30 supports the entire periphery of the battery pack 10.

[0023] The battery pack 10 includes a battery case 11. The battery case 11 includes an upper case 12 and a lower case 15. An upper wall 13A (see FIG. 2) of the upper case 12 also functions as a floor panel for the vehicle interior. That is, a floor carpet 52 is laid on the upper wall 13A.

[0024] A seat bracket 39 is fixed to the frame 30. The seat bracket 39 extends, for example, in the vehicle width direction. The seat bracket 39 is provided as a pair, for example, side by side in the vehicle front-rear direction.

[0025] A floor carpet 52 is laid on the frame 30 and the battery pack 10. Furthermore, a seat 54 is fastened to the seat bracket 39 through fastening holes 52A in the floor carpet.

[0026] Additionally, a seal strip 20 is provided on the upper case 12 of the battery pack 10. The seal strip 20 is provided in a ring shape along the side wall 13B (see FIG. 2) of the upper case 12. FIG. 4 shows an example of a side member 32, which is a component of the frame 30. The seal strip 20 abuts against an inner wall 32A of the side member 32. In other words, the seal strip 20 spans between the side member 32 and the battery pack 10.

[0027] 4, the gap between the battery pack 10 and the frame 30 is sealed around the entire periphery by the sealing strip 20. Therefore, the sealing strip 20 prevents external noise such as road noise from leaking into the vehicle cabin through the gap between the battery pack 10 and the frame 30.

[0028] As described above, since the upper wall 13A of the battery pack 10 (see FIG. 2) also serves as a floor panel, liquid spilled onto the floor carpet 52 seeps out of the floor carpet 52 and reaches the battery pack 10. Furthermore, as illustrated in FIG. 4, the liquid 60 flows into the seal strip 20 that spans between the battery pack 10 and the frame 30. As will be described later, the seal strip side 21 (see FIG. 2) extends obliquely along the vehicle's fore-and-aft direction in a side view of the vehicle. Therefore, the liquid is discharged obliquely downward along the oblique seal strip 20.

[0029] 2. Frame Fig. 5 illustrates a perspective view of the frame 30 alone. Fig. 6 illustrates a perspective view of the frame 30 alone, as seen from the front-to-back direction opposite to that of Fig. 5. Fig. 4 illustrates a cross-sectional view taken along line AA in Fig. 1.

[0030] The frame 30 has, for example, a hollow structure. For example, the cross section of the frame 30 is rectangular. A fastening hole 41A is drilled in the bottom wall 41 of the frame 30. The fastening hole 41A penetrates the bottom wall 41 in the thickness direction.

[0031] A weld nut 40 is provided inside the frame 30. The weld nut 40 is coaxial with the fastening hole 41A. As will be described later, the fastening holes 14A and 17A of the battery pack 10 are aligned with the fastening hole 41A. Then, a bolt 45 (fastener) is threaded into the fastening holes 14A, 17A, and 41A. This fastens the battery pack 10 to the frame 30.

[0032] 5 and 6, the frame 30 is a frame-shaped framework component and includes a pair of side members 32, 32, a front cross member , and a rear cross member .

[0033] The pair of side members 32 extend in the front-rear direction of the vehicle. The side members 32 are disposed at both ends of the vehicle interior in the vehicle width direction. The battery pack 10 is disposed between the pair of side members 32. The side members 32 are hollow members. The side members 32 are formed, for example, from square pipes. The front and rear ends of the side members 32 are closed by metal plates or the like.

[0034] A discharge hole 32B is formed in the side members 32. The discharge hole 32B penetrates, for example, the side members 32 in the vehicle width direction. The discharge hole 32B is provided, for example, in the rear end portion of the side members 32. For example, a cylindrical inner wall may be attached to the discharge hole 32B. As will be described later, a seal line SL formed by the seal strip 20 passes through at least a portion of the discharge hole 32B.

[0035] The front ends of the side members 32 are connected to the front cross member 34. The pair of side members 32 are joined to the front cross member 34 by, for example, welding. For example, the front cross member 34 has a smaller height dimension than the side members 32.

[0036] The front cross member 34 extends in the vehicle width direction. The front cross member 34 is a hollow member. The front cross member 34 is made of, for example, a square pipe. As shown by openings 34A in Figures 5 and 6, both ends of the front cross member 34 in the vehicle width direction are open.

[0037] Additionally, a discharge hole 34B is formed in an inner wall 34C of the front cross member 34. The discharge hole 34B penetrates the inner wall 34C in the vehicle longitudinal direction. For example, the discharge hole 34B is provided at both ends of the front cross member 34 in the vehicle width direction. As will be described later, a seal line SL formed by the seal strip 20 passes through at least a portion of the discharge hole 34B.

[0038] The rear ends of the side members 32 are connected to the rear cross member 36. The pair of side members 32 are joined to the rear cross member 36 by, for example, welding. For example, the rear cross member 36 has a smaller height dimension than the side members 32.

[0039] The rear cross member 36 extends in the vehicle width direction. The central portion of the rear cross member 36 in the vehicle width direction protrudes further toward the rear of the vehicle than both end portions in the vehicle width direction. The rear cross member 36 is a hollow member. The rear cross member 36 is formed, for example, by bending a square pipe. As shown by openings 36A in Figures 5 and 6, both ends of the rear cross member 36 in the vehicle width direction are open.

[0040] Additionally, a discharge hole 36B is formed in an inner wall 36C of the rear cross member 36. The discharge hole 36B penetrates the inner wall 36C in the vehicle longitudinal direction. For example, the discharge hole 36B is provided at both end portions of the rear cross member 36 in the vehicle width direction. As will be described later, a seal line SL formed by the seal strip 20 passes through at least a portion of the discharge hole 36B.

[0041] As will be described later, the rear end of the seal strip side 21 (see FIG. 2) abuts against the inner side wall 36C of the rear cross member 36. A discharge hole 36B is formed in the inner side wall 36C at the abutting point. In other words, the discharge hole 36B is located at the end of the seal strip side 21, which is arranged in a downward inclined manner.

[0042] 3. Battery pack 2 and 3, battery pack 10 is a large box-shaped component. For example, battery pack 10 is disposed on the floor of a vehicle compartment. Battery pack 10 supplies electric power to a rotating electric machine (not shown) that serves as a drive source for the vehicle.

[0043] The battery pack 10 is supported by a frame 30. Referring to Figures 1 and 4, for example, a plurality of fastening holes 14A, 17A are drilled in the upper flange 14 and the lower flange 17 of the battery pack 10. The upper flange 14 and the lower flange 17 are formed around the entire periphery of the battery pack 10. The fastening holes 14A, 17A are also formed around the entire periphery of the upper flange 14 and the lower flange 17. Therefore, the battery pack 10 is fastened and supported to the frame 30 around the entire periphery.

[0044] 4, the battery pack 10 includes a battery case 11 and a plurality of battery cells 50. The battery case 11 houses the battery cells 50. The battery cells 50 are formed of, for example, nickel-metal hydride secondary batteries, lithium-ion secondary batteries, all-solid-state batteries, or the like.

[0045] 2 and 3, the battery case 11 includes an upper case 12 and a lower case 15. The lower case 15 includes a tray portion 16 and a lower flange 17. The lower case 15 is made of a metal panel such as an aluminum panel. For example, the lower case 15 is formed by press working. A plurality of battery cells 50 are arranged in the tray portion 16.

[0046] The lower flange 17 is disposed on the periphery of the tray portion 16. For example, the lower flange 17 surrounds the entire periphery of the tray portion 16. The lower flange 17 is also provided on the upper end of the tray portion 16.

[0047] The upper case 12 is a lid portion of the battery case 11. For example, the upper case 12 is made of a metal panel such as an aluminum panel. For example, the upper case 12 is formed by press working.

[0048] The upper case 12 includes a cover portion 13 and an upper flange 14. The cover portion 13 is placed over the tray portion 16 of the lower case 15. The cover portion 13 includes a top wall 13A and a side wall 13B. The top wall 13A extends horizontally. The side wall 13B surrounds the entire periphery of the top wall 13A. Referring to FIG. 4, the side wall 13B stands upright relative to the top wall 13A.

[0049] An upper flange 14 is disposed on the periphery of the cover portion 13. For example, the upper flange 14 is provided at the lower end of the cover portion 13. The upper flange 14 is provided around the entire periphery of the cover portion 13.

[0050] 4, a seal material 19 is attached between the upper flange 14 and the lower flange 17. The seal material 19 is attached around the entire periphery of the upper flange 14 and the lower flange 17. In this way, the battery cell 50 is sealed in the battery case 11.

[0051] The upper wall 13A of the upper case 12 also serves as a floor panel for the vehicle interior. For this reason, a reinforcing component (not shown) may be fixed to the inner surface of the upper wall 13A. The inner surface of the upper wall 13A refers to the surface facing the battery cells 50.

[0052] A seal strip 20 is also provided around the entire periphery of the side wall 13B. The seal strip 20 seals the gap between the battery pack 10 and the frame 30 (see FIGS. 5 and 6).

[0053] 4.Sealing strip 2 and 3, the sealing strip 20 is a frame-shaped member. The sealing strip 20 is made of an elastic material such as rubber. The sealing strip 20 is stretched across the frame 30 and the battery pack 10.

[0054] The seal strip 20 includes a pair of seal strip sides 21, 21, a seal strip front 23, a seal strip rear 22, and a connecting portion 24. The pair of seal strip sides 21, 21 extend in the front-to-rear direction of the vehicle. The seal strip sides 21, 21 also extend parallel to a side member 32 of the frame 30 (see FIG. 5).

[0055] The front seal strip 23 extends in the vehicle width direction. The front seal strip 23 extends parallel to the front cross member 34 of the frame 30. That is, the front seal strip 23 is disposed in the gap between the front cross member 34 and the front end of the battery pack 10.

[0056] The rear seal strip 22 extends in the vehicle width direction. The rear seal strip 22 extends along the rear cross member 36 of the frame 30. That is, the rear seal strip 22 is disposed in the gap between the rear cross member 36 and the rear end of the battery pack 10.

[0057] The seal strip sides 21, 21 extend at an incline along the vehicle's fore-and-aft direction in a side view of the vehicle. For example, the seal strip sides 21, 21 slope downward, becoming lower toward the rear in the vehicle's fore-and-aft direction. By sloping downward, liquid on the seal strip sides 21, 21 can easily flow rearward in a vehicle whose main movement is forward movement. Furthermore, the seal strip sides 21, 21 extend linearly from the front end to the rear end of the upper case 12.

[0058] 3, the seal strip front 23 is installed on the side wall 13B so as to have an arched shape. That is, the seal strip front 23 has an apex at the center in the vehicle width direction and becomes lower as it goes outward in the vehicle width direction.

[0059] Both ends of the seal strip front 23 in the vehicle width direction are the lowest among the components. On the other hand, the front ends of the seal strip side 21, 21 are the highest among the components. To fill this height difference, connecting portions 24 are provided. That is, both ends of the seal strip front 23 in the vehicle width direction are connected to the lower ends of the connecting portions 24. The front ends of the seal strip side 21 are connected to the upper ends of the connecting portions 24. By providing the connecting portions 24, the seal strip 20 can surround the side wall 13B without any gaps.

[0060] 2, the rear seal strip 22 is installed on the side wall 13B so as to have an arched shape. That is, the rear seal strip 22 has its peak at the center in the vehicle width direction and becomes lower as it goes outward in the vehicle width direction. Liquid dripped onto the rear seal strip 22 flows down from the center in the vehicle width direction toward the ends in the vehicle width direction. Both ends of the rear seal strip 22 in the vehicle width direction are connected to the rear ends of the side seal strips 21, 21.

[0061] As illustrated in Figure 4, the tip of the seal strip 20 abuts against the inner side wall 32A of the frame 30. The abutment points of the seal strip 20 are indicated by seal lines SL in Figures 5 and 6. As indicated by the seal lines SL, the tip of the seal strip 20 abuts seamlessly against the inner side walls 32A of the side members 32, 32, the inner side wall 34C of the front cross member 34, and the inner side wall 36C of the rear cross member 36. This suppresses leakage of external noise into the vehicle cabin.

[0062] 2, 3, 5, and 6, the rear end of the seal strip side 21 abuts against the inner side wall 36C of the rear cross member 36. A discharge hole 34B is drilled in the inner side wall 36C at the location where the rear end of the seal strip side 21 abuts. In other words, the discharge hole 34B is connected to the downstream end of the seal strip side 21. Therefore, liquid that has flowed down the seal strip side 21 enters the rear cross member 36 through the discharge hole 34B. The liquid is then discharged to the outside of the vehicle through an opening 36A in the rear cross member 36.

[0063] Furthermore, a discharge hole 32B is provided at the rear end of the side member 32. The seal strip side 21 passes through a part of the discharge hole 32B. Therefore, the liquid flowing down the seal strip side 21 is also discharged outside the vehicle through the discharge hole 32B.

[0064] In addition, both ends of the rear seal strip 22 in the vehicle width direction abut against the inner side walls 32A of the side members 32. Drain holes 32B are drilled in the inner side walls 32A at the locations where the inner side walls 32A abut against both ends of the rear seal strip 22 in the vehicle width direction. Therefore, liquid that has flowed down the rear seal strip 22 is discharged to the outside of the vehicle through the drain holes 32B. In addition, liquid that has flowed down the rear seal strip 22 is also discharged to the outside of the vehicle through the drain holes 36B.

[0065] 3 and 5, discharge holes 34B are drilled at both ends of the front cross member 34 in the vehicle width direction. As shown by the seal line SL, the seal strip front 23 passes through a portion of the discharge hole 34B. Therefore, liquid flowing down the seal strip front 23 flows from the discharge hole 34B into the front cross member 34. The liquid that has flowed into the front cross member 34 is then discharged outside the vehicle through the opening 34A.

[0066] In this way, in the vehicle undercarriage structure according to this embodiment, the seal strip 20 extends non-horizontally. Therefore, liquid that drips onto the seal strip 20 moves along the inclination of the seal strip 20.

[0067] Instead of connecting the discharge hole 36B to the downstream end of the seal strip 20, a water-absorbing material such as a sponge may be installed. For example, the water-absorbing material is placed near a heat source inside the vehicle. For example, in a heat exchange system, a pipe through which a high-temperature refrigerant compressed by a compressor flows is provided at the rear of the vehicle. The water-absorbing material is placed near this refrigerant pipe.

[0068] 5. First Alternative to Seal Strip (U-shaped Seal) 4, the leading end of the sealing strip 20 hangs down from the root, so that the inner wall 32A of the frame comes into contact with the liquid 60.

[0069] 7, a seal strip 20 having a U-shaped cross section may be disposed between the battery pack 10 and the frame 30. In this configuration, the seal strip 20 can be used as a gutter. That is, contact between the battery pack 10 or the frame 30 and the liquid 60 is suppressed.

[0070] In the above-described embodiment, the sealing strip 20 is attached to the battery pack 10. However, in the vehicle undercarriage structure according to the present embodiment, it is sufficient that the sealing strip 20 is stretched across the frame 30 and the battery pack 10. Therefore, instead of the above-described embodiment, the sealing strip 20 may be attached to the inner side walls 32A, 34C, 36C of the frame 30. [Explanation of symbols]

[0071] 10 battery pack, 11 battery case, 12 upper case, 15 lower case, 20 seal strip, 21 seal strip side, 22 seal strip rear, 23 seal strip front, 24 connection part, 30 frame, 32 side member, 32A inner wall of side member, 32B, 34B, 36B discharge hole, 34 front cross member, 34A, 36A opening, 34C inner wall of front cross member, 36 rear cross member, 36C inner wall of rear cross member.

Claims

1. a pair of side members extending in a vehicle front-rear direction and disposed at both ends of a vehicle interior in a vehicle width direction; a battery pack disposed between the pair of side members; a seal strip spanning the side member and the battery pack; Equipped with The seal strip extends obliquely along the vehicle longitudinal direction in a vehicle side view. Vehicle undercarriage.

2. The vehicle underbody structure according to claim 1, The sealing strip has a downward inclination that becomes lower as it goes rearward in the vehicle front-rear direction. Vehicle undercarriage.

3. The vehicle underbody structure according to claim 2, The rear ends of the pair of side members are connected to a cross member extending in the vehicle width direction, The cross member is a hollow member, and both ends of the cross member in the vehicle width direction are open, a rear end of the sealing strip abutting against an inner wall of the cross member; A discharge hole is provided in the inner wall of the cross member at a contact point with the rear end of the sealing strip. Vehicle undercarriage.

4. The vehicle underbody structure according to claim 3, a rear seal strip is installed in the gap between the cross member and the rear end of the battery pack; The rear seal strip is installed so as to have an arched shape that has a vertex at the center in the vehicle width direction and becomes lower as it goes outward in the vehicle width direction. Vehicle undercarriage.

5. The vehicle underbody structure according to claim 1, The sealing strip has a U-shaped cross section. Vehicle undercarriage.

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