Vehicle rear structure

Abstract

This invention provides a rear structure for a vehicle. A reinforcing member and a lower protrusion are provided in the lower housing of a battery pack. The reinforcing member extends along the longitudinal direction of the vehicle between battery modules arranged along the vehicle's width. The lower protrusion, adjacent to the reinforcing member in the vehicle's width direction, is positioned opposite a safety valve for each battery cell and protrudes downwards from the vehicle. The lower protrusion, positioned along the longitudinal direction for each battery module, communicates with the outside at the rear end of the battery pack, allowing exhaust fumes released from the safety valves to be discharged outside the vehicle via the lower protrusion. In this invention, the lower protrusion constituting the exhaust path can be protected against collision loads input along the vehicle's longitudinal and width directions.

Description

Technical Field

[0001] This invention relates to the rear structure of a vehicle. Background Technology

[0002] Japanese Patent Application Publication No. 2019-135687 discloses technology related to vehicles equipped with energy storage modules. In this prior art, the energy storage module consists of multiple energy storage cells, and each energy storage cell has a safety valve at its upper end that releases gas when the gas pressure inside the energy storage cell exceeds a predetermined value. Furthermore, an exhaust duct communicating with the outside of the vehicle is provided at the upper end of the energy storage module, and the multiple safety valves are covered by this exhaust duct. Thus, the gas (exhaust gas) discharged through the safety valves is released to the outside of the vehicle through this exhaust duct.

[0003] However, when housing multiple energy storage modules within a battery casing, a smoke exhaust path needs to be installed within the casing. Therefore, the shape of the battery casing needs to be studied. Summary of the Invention

[0004] In view of the above facts, the present invention aims to provide a vehicle rear structure having a battery housing having an exhaust smoke path provided at the bottom and protecting the exhaust smoke path.

[0005] Regarding the vehicle rear structure involved in the first approach, the battery housing includes a lower housing that constitutes a receiving portion in which multiple battery modules arranged along the vehicle's longitudinal direction are arranged along the vehicle's width direction. The vehicle rear structure is configured to include: a longitudinal frame disposed on the lower wall of the lower housing and extending along the vehicle's longitudinal direction between the battery modules arranged along the vehicle's width direction; and a lower protrusion disposed on the lower wall of the lower housing and disposed between adjacent longitudinal frames in the vehicle's width direction. The lower protrusion is positioned opposite a safety valve disposed on multiple battery cells constituting the battery modules and capable of releasing pressure within the battery cells, protruding towards the lower side of the vehicle and communicating with the outside of the vehicle. The lower protrusion is provided along the vehicle's longitudinal direction for each battery module and communicates with the outside at the rear end of the battery housing.

[0006] In the rear structure of the vehicle according to the first embodiment, the battery housing includes a lower housing that constitutes a receiving portion in which multiple battery modules arranged along the vehicle's longitudinal direction are arranged along the vehicle's width direction. A longitudinal frame and a lower protrusion are provided on the lower wall of the lower housing. The longitudinal frame extends along the vehicle's longitudinal direction between the battery modules arranged along the vehicle's width direction. The lower protrusion is located between adjacent longitudinal frames in the vehicle's width direction, forming a position opposite to a safety valve disposed on one of the multiple battery cells constituting the battery module and capable of releasing pressure within the battery cell, and protrudes downward toward the vehicle's underside.

[0007] The lower protrusion is provided along the front-rear direction of the vehicle for each battery module, and can communicate with the outside at the rear end of the battery housing. That is, in this method, the lower protrusion becomes a smoke exhaust flow path, and the smoke released (ejected) from the safety valve can be discharged to the outside of the vehicle through the lower protrusion.

[0008] In this embodiment, the lower protrusion is positioned between adjacent longitudinal frames in the vehicle width direction. By extending the longitudinal frames along the vehicle's longitudinal direction on the lower wall of the lower housing, the rigidity of the lower housing can be improved against collision loads input in the vehicle's longitudinal direction. Furthermore, by positioning the lower protrusion between adjacent longitudinal frames in the vehicle width direction, the lower protrusion can be protected against collision loads input in the vehicle width direction. As a result, in this embodiment, the lower protrusion constituting the exhaust path can be protected against collision loads input in both the vehicle's longitudinal and width directions.

[0009] Regarding the vehicle rear structure involved in the second method, in the vehicle rear structure involved in the first method, the width dimension of the lower protrusion in the vehicle width direction decreases as it moves towards the lower side of the vehicle, and the width dimension of the lowermost end of the lower protrusion becomes greater than or equal to the outer dimension of the safety valve along the vehicle width direction.

[0010] In the rear vehicle structure described in the second approach, the width dimension of the lower protrusion in the vehicle width direction decreases as it approaches the lower side of the vehicle. Therefore, the width dimension of the lower protrusion is the smallest at the bottom, but the width dimension of the bottom of the lower protrusion is greater than the size of the safety valve's outer dimensions along the vehicle width direction.

[0011] Since the lower protrusion is positioned opposite the safety valve, by making the width of the lowermost end of the lower protrusion greater than the outer dimensions of the safety valve, the impact acting on the lower protrusion can be mitigated when smoke is ejected from the safety valve, and the smoke can be reliably guided into the lower protrusion.

[0012] As described above, the rear structure of the vehicle of the present invention can include a battery housing having an exhaust smoke path provided at the bottom and protecting the exhaust smoke path. Attached Figure Description

[0013] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, wherein:

[0014] Figure 1 This is a schematic top view showing the rear structure of the vehicle according to this embodiment.

[0015] Figure 2 This is a schematic perspective view showing the battery pack disposed in the rear structure of the vehicle according to this embodiment;

[0016] Figure 3 It is a section along the front-to-back direction of the vehicle. Figure 1 A schematic cross-sectional view of the rear structure of a vehicle.

[0017] Figure 4 It is a section along the width of the vehicle. Figure 1 A schematic cross-sectional view of the rear structure of a vehicle.

[0018] Figure 5 It is cut along line AA Figure 1 A schematic sectional view of the rear structure of the vehicle; and

[0019] Figure 6 It is Figure 4 A partially enlarged sectional view. Detailed Implementation

[0020] Hereinafter, the rear structure of a vehicle according to an embodiment of the present invention will be described using the accompanying drawings. Furthermore, identical or equivalent parts in the drawings will be labeled with the same or similar reference numerals, and repeated descriptions will be omitted. Additionally, when there are multiple identical or equivalent parts in the drawings, only a few will sometimes be labeled for ease of observation. Furthermore, arrow FR appropriately shown in each drawing indicates the front side in the vehicle's longitudinal direction, and arrow UP indicates the upper side in the vehicle's vertical direction. Arrow RH indicates the right side in the vehicle's width direction; in this embodiment, it indicates the outer side in the vehicle's width direction. Hereinafter, only the longitudinal, vertical, and left-right directions will be used in the description, unless otherwise specified, referring to the longitudinal direction of the vehicle, the vertical direction of the vehicle, and the left-right direction (vehicle width direction).

[0021] The structure of the rear of the vehicle

[0022] First, the structure of the rear structure of the vehicle in this embodiment will be explained.

[0023] Figure 1This is a partial schematic top view of a vehicle 10 having the rear structure 14 of this embodiment. Figure 2 This is a schematic perspective view of the battery pack (battery casing) 18 mounted on the vehicle 10.

[0024] like Figure 1 As shown, the battery pack 18 mounted on vehicle 10 is as follows Figure 2 As shown, the vehicle has multiple (four in this embodiment) battery modules 20 arranged in the vehicle width direction. Furthermore, gaps GP5 are formed between adjacent battery modules 20 in the vehicle width direction. In this embodiment, since there are four battery modules 20, there are three gaps GP5 formed between them.

[0025] like Figure 1 As shown, each battery module 20 has a plurality of battery cells 22, which are arranged in the battery module 20 along the front-rear direction of the vehicle. That is, the battery pack 18 is a structure in which a plurality of battery modules 20 having a plurality of battery cells 22 arranged in the front-rear direction of the vehicle are arranged in the width direction of the vehicle.

[0026] Figure 3 It is Figure 1 The diagram shows a cross-sectional view of the rear structure 14 of the vehicle when cut along the longitudinal direction of the vehicle. Figure 4 It is Figure 1 The diagram shows a cross-sectional view of the rear structure 14 of the vehicle when cut along the width of the vehicle. (See diagram below.) Figure 3 , Figure 4 As shown, the battery pack 18 has a lower housing 24 and an upper cover 26. Furthermore, in Figure 1 , Figure 2 The illustration of the upper cover 26 is omitted in the text.

[0027] like Figure 3 , Figure 4 As shown, the lower housing 24 is a component with a box-shaped receiving portion 23 capable of housing the battery module 20, and is configured to include a lower plate (lower wall portion) 24L, a front plate 24F, a rear plate 24R, and a pair of left and right side plates 24S. The lower plate 24L is a plate-shaped portion that supports the battery module 20 from below. The front plate 24F and the rear plate 24R are plate-shaped portions that are erected from the front and rear ends of the lower plate 24L, respectively, and the side plates 24S are plate-shaped portions that are erected from both sides of the lower plate 24L in the vehicle width direction. In addition, the upper surface of the lower housing 24 is open, and the flange portion 25 extends from the periphery of the lower housing 24 toward the outside of the receiving portion 23.

[0028] On the other hand, the upper cover 26 is a cover-like component that closes the upper surface of the lower housing 24. It is formed including a receiving portion 23 that is integral with the lower housing 24, and has the same structure as the lower housing 24. A flange portion 27 extends from the periphery of the upper cover 26 toward the outside of the receiving portion 23. This flange portion 27 can engage with the flange portion 25 formed on the lower housing 24 in an mating state.

[0029] like Figure 3 As shown, at the rear end of the lower housing 24, the area of ​​the flange portion 25 is larger than the area of ​​the flange portion 27 of the upper cover 26, and a gap 29 communicating with the receiving portion 23 is provided between the upper plate 26U of the upper cover 26 and the flange portion 25 of the lower housing 24.

[0030] in addition, Figure 6 It is Figure 4 A partially enlarged sectional view. For example... Figure 6 As shown, safety valves 35 are provided at the center of the length direction (vehicle width direction) of the battery cell 22 on the lower surface side. These safety valves 35 allow gas to be released when the gas pressure inside the battery cell 22 exceeds a predetermined value.

[0031] On the other hand, such as Figure 4 , Figure 6 As shown, the lower plate 24L of the lower housing 24 has a plurality of (the same number as the battery module 20) lower protrusions 30 that protrude toward the lower side of the vehicle. That is, for the lower protrusions 30, the lower housing 24 is separated from the lower surface of the battery cell 22, thereby forming a gap GP1.

[0032] Furthermore, the lower protrusions 30 are formed in the battery module 20 extending in the vehicle's longitudinal direction, i.e., the direction in which the battery cells 22 are arranged. The length of the lower protrusions 30 in the vehicle's longitudinal direction is longer than the length of the battery module 20 in the vehicle's longitudinal direction. Figure 3 The area near the front panel 24F extends continuously along the vehicle's longitudinal direction to the area near the rear panel 24R. Furthermore, as shown... Figure 4 , Figure 6 As shown, the lower protrusion 30 protrudes downward at the center of each battery module 20 in the vehicle width direction. That is, the lower protrusion 30 and the safety valve 35 are formed opposite to each other.

[0033] Here, as Figure 6As shown, the cross-sectional shape of the lower protrusion 30, cut along the vehicle width direction, is a flat trapezoidal shape with the upper base longer than the lower base. The height dimension H1 of the trapezoidal shape is lower than the width dimension (the dimension in the vehicle width direction) W of the lower protrusion 30. Furthermore, the width dimension of the lower protrusion 30 decreases towards the lower side of the vehicle. Additionally, the width dimension W1 of the lowermost end of the lower protrusion 30 is larger than the overall dimension L of the safety valve 35 along the vehicle width direction.

[0034] Here, the lower protrusion 30 is provided along the front-rear direction of the vehicle for each battery module 20, and can communicate with the outside at the rear end of the battery pack 18. That is, in this embodiment, the lower protrusion 30 becomes part of the exhaust flow path 32, and the exhaust smoke released (ejected) from the safety valve 35 can be discharged to the outside of the vehicle through the lower protrusion 30.

[0035] Thus, the gap GP1, separated from the lower surface of the battery cell 22 by the lower protrusion 30, extends along the longitudinal direction of the vehicle, thereby forming part of the smoke exhaust path 32. In the event that smoke-containing gas (hereinafter referred to as "smoke") is generated in the battery cell 22 for some reason, smoke is discharged from the safety valve 35 provided in the battery cell 22. Therefore, the smoke generated in the battery cell 22 flows into the gap GP1 formed by the lower protrusion 30.

[0036] like Figure 1 As shown, multiple battery modules 20 are arranged in the vehicle width direction, with gaps GP5 formed between adjacent battery modules 20 in the vehicle width direction. Reinforcing members (longitudinal frames) 40 are respectively disposed in the gaps GP5. Since the gaps GP5 are located between adjacent battery modules 20 in the vehicle width direction, the lower protrusion 30 is disposed between adjacent reinforcing members 40 in the vehicle width direction.

[0037] Here, as Figure 6 As shown, the cross-sectional shape of the reinforcing member 40 when cut along the vehicle width direction is a roughly cap-shaped cross-section with an open lower side. Figure 1 As shown, the reinforcing member 40 has a length that extends to the vicinity of the front panel 24F and the rear side panel 24R of the lower housing 24. The front end 40A and the rear end 40B of the reinforcing member 40 are respectively engaged with the front panel 24F and the rear side panel 24R of the lower housing 24 via engaging members 42. Thus, the reinforcing member 40 reinforces the battery pack 18.

[0038] like Figure 5As shown, the engaging member 42 has a first partition 42D between the engaging surface 42A, which contacts the lower plate 24L surface of the lower housing 24, and the engaging surface 42B, which contacts the rear plate 24R surface of the lower housing 24. When viewed in a cross-section along the vehicle's longitudinal direction, the first partition 42D is formed at an angle, creating a gap GP2 between the first partition 42D and the lower housing 24. This gap GP2 is continuous in the vehicle width direction and communicates with the gap GP1 between the lower surface of the battery cell 22 and the lower protrusion 30. That is, this gap GP2 forms part of the exhaust flow path 32.

[0039] On the other hand, such as Figure 6 As shown, a cell support 44 is formed at the location where the reinforcing member 40 is provided on the lower plate 24L of the lower housing 24. The cell support 44 causes the lower plate 24L of the lower housing 24 to be convex downwards at the position corresponding to the reinforcing member 40. Furthermore, a flange plate 40F of the reinforcing member 40 is joined to the cell support 44, and the open portion on the lower side of the reinforcing member 40 is closed to form a closed cross-section 41. Additionally, the height dimension H2 of the reinforcing member 40 is greater than the width dimension W2.

[0040] in addition, Figure 1 The front end 40A and rear end 40B of the reinforcing member 40 shown are open, and... Figure 5 The gap GP2 shown is connected. That is, the closed section 41 formed by the reinforcing member 40 and the cell base 44 is connected to... Figure 5 The gap GP2 shown is connected and forms part of the smoke exhaust path 32.

[0041] Here, as Figure 5 As shown, a connector block 50 is provided on the rear end side of the lower housing 24. Figure 1 As shown, the front edge (the edge on the front side of the vehicle) of the connector block 50 is straight along the vehicle width direction. In contrast, the rear edge (the edge on the rear side of the vehicle) of the connector block 50 is curved so as to bulge towards the rear of the vehicle from the center in the vehicle width direction. That is, the central portion 50C of the connector block 50 in the vehicle width direction is formed to be longer in the vehicle front-rear direction than the two ends 50E in the vehicle width direction.

[0042] In addition, such as Figure 5 As shown, a smoke exhaust valve 52 is provided on the outer side of the connector block 50 in the vehicle width direction. A cover plate 54 is installed on the connector block 50 from the battery pack 18 to the smoke exhaust valve 52, and the cover plate 54 and the connector block 50 form part of the smoke exhaust flow path 32.

[0043] An upward protrusion 58 is formed on the cover plate 54. The upward protrusion 58 is formed by bending the central portion of the vehicle width direction upward on the front side of the vehicle. By forming the upward protrusion 58, a gap GP4 is formed between the cover plate 54 and the connector block 50. This gap GP4 allows smoke to move in the front-rear direction of the vehicle, thereby forming part of the smoke exhaust path 32.

[0044] Furthermore, a second partition 42E is provided on the joining member 42 that engages with the rear plate 24R of the lower housing 24. The second partition 42E is formed in the vehicle width direction at a position corresponding to the upper protrusion 58. In addition, the second partition 42E is separated from the rear plate 24R of the lower housing 24 and is continuous with the first partition 42D. Furthermore, a gap GP3 is formed between the second partition 42E and the rear plate 24R of the lower housing 24.

[0045] Therefore, the exhaust flow path 32 in the battery pack 18 is formed to extend from the gap GP1 between the lower surface of the battery cell 22 and the lower protrusion 30, through the gap GP2 between the first partition 42D and the rear plate 24R of the lower housing 24, the gap GP3 between the second partition 42E and the rear plate 24R of the lower housing 24, and the gap GP4 between the cover plate 54 and the lower housing 24 to the exhaust valve 52.

[0046] When the internal pressure of the exhaust flow path 32 is higher than the external air pressure of the exhaust flow path 32 by a specified value, the exhaust valve 52 opens. That is, when smoke flows into the exhaust flow path 32 and causes its internal pressure to rise above the specified value, the exhaust valve 52 opens, allowing the gas inside the exhaust flow path 32 to be discharged to the outside.

[0047] The function and effect of the rear structure of a vehicle

[0048] Next, the function and effects of the rear structure of the vehicle involved in this embodiment will be explained.

[0049] In application Figure 1 In the vehicle 10 of the rear structure 14 of this embodiment, a battery module 20 is composed of a plurality of battery cells 22. The battery cells 22 are arranged in the battery module 20 along the vehicle's longitudinal direction, and the battery module 20 is arranged along the vehicle's width direction. This allows for the efficient arrangement of a plurality of battery cells 22 in both the vehicle's longitudinal and width directions. In particular, since the battery cells 22 in the battery module 20 are arranged in the vehicle's longitudinal direction, the number of battery cells 22 in each row can be increased compared to a structure in which the battery cells 22 are arranged along the vehicle's width direction.

[0050] exist Figure 5The battery cell 22 shown does not produce smoke under normal conditions. However, if smoke is produced under certain circumstances, it is discharged from the center of the lower surface of the battery cell 22 in the vehicle width direction. The smoke flows into the gap GP1 between the lower protrusion 30 of the lower housing 24 of the battery pack 18 and the lower surface of the battery cell 22. Furthermore, the smoke flows to the smoke exhaust valve 52 via gaps GP2 and GP3 respectively located on the rear plate 24R side of the lower housing 24, and gap GP4 respectively located between the cover plate 54 and the connector block 50 at the rear end of the lower housing 24. Gap GP1 to gap GP4 each constitute part of the smoke exhaust flow path 32. If the internal pressure of the smoke exhaust flow path 32 is higher than the external pressure, the smoke is discharged from the smoke exhaust valve 52.

[0051] In this embodiment, as Figure 4 , Figure 6 As shown, a reinforcing member 40 and a lower protrusion 30 are provided on the lower plate 24L of the lower housing 24. The reinforcing member 40 extends along the longitudinal direction of the vehicle between the battery modules 20 arranged along the width direction of the vehicle.

[0052] On the other hand, the lower protrusion 30 is disposed between adjacent reinforcing members 40 in the vehicle width direction, and is provided for each of the plurality of battery cells 22 constituting the battery module 20. It is formed at a position opposite to the safety valve 35 that can release the pressure inside the battery cell 22, and protrudes toward the lower side of the vehicle.

[0053] Furthermore, the lower protrusion 30 is provided along the front-rear direction of the vehicle for each battery module 20, and can communicate with the outside at the rear end of the battery pack 18. That is, in this embodiment, the lower protrusion 30 serves as a smoke exhaust path 32, and the smoke released (ejected) from the safety valve 35 can be discharged to the outside of the vehicle through the lower protrusion 30.

[0054] Furthermore, in this embodiment, the lower protrusion 30 is disposed between the reinforcing members 40. By extending the reinforcing members 40 along the vehicle's longitudinal direction at the lower plate 24L of the lower housing 24, the rigidity of the lower housing 24 can be improved against collision loads input along the vehicle's longitudinal direction. Additionally, by disposing the lower protrusion 30 between adjacent reinforcing members 40 in the vehicle's width direction, the lower protrusion 30 can be protected against collision loads input along the vehicle's width direction. As a result, in this embodiment, the lower protrusion 30 constituting the smoke exhaust path 32 can be protected against collision loads input along both the vehicle's longitudinal and width directions.

[0055] As described above, in this embodiment, a battery pack 18 is provided that accommodates multiple battery modules 20 and has a smoke exhaust path 32 at the bottom and protects the smoke exhaust path 32.

[0056] In particular, the height dimension H2 of the reinforcing member 40 is greater than the width dimension W2. The reinforcing member 40 is formed within the gap GP5 provided between adjacent battery modules 20 in the vehicle width direction, thus the width dimension W2 is predetermined. Compared to setting the height dimension H2 of the reinforcing member 40 to be the same size as the width dimension W2, by setting the height dimension H2 to be larger than the width dimension W2, the moment of inertia of the section in the reinforcing member 40 can be increased, suppressing deformation. Therefore, for collision loads input along the vehicle's longitudinal direction, the rigidity of the lower housing 24 can be further improved, protecting the exhaust smoke path 32.

[0057] Furthermore, in this embodiment, a downward protrusion 30 is formed in the lower plate 24L of the lower housing 24 in the battery pack 18. This improves the rigidity of the lower plate 24L itself.

[0058] Furthermore, in this embodiment, by providing a lower protrusion 30 protruding from the lower plate 24L of the lower housing 24 toward the vehicle's lower side, a gap GP1 is provided between the lower surface of the battery cell 22 and the lower plate 24L of the lower housing 24. In this embodiment, when exhaust smoke is emitted from the safety valve 35 of the battery cell 22, by ejecting exhaust smoke into the lower protrusion 30, the impact toward the battery cell 22 generated when exhaust smoke is emitted from the safety valve 35 can be reduced compared to the case where the lower plate 24L of the lower housing 24 does not have the lower protrusion 30.

[0059] Here, the cross-sectional shape of the lower protrusion 30, which is cut along the width direction of the vehicle, is set to a flat trapezoidal shape with the upper base longer than the lower base, and the width dimension W of the lower protrusion 30 decreases as it moves towards the lower side of the vehicle. Moreover, the width dimension W1 of the lowermost end of the lower protrusion 30 is larger than the outer dimension L of the safety valve 35.

[0060] Since the lower protrusion 30 is positioned opposite the safety valve 35, by making the width W1 of the lowermost end of the lower protrusion 30 larger than the outer dimension L of the safety valve 35, the width W1 of the lower protrusion 30 is larger than the outer dimension L of the safety valve 35. Accordingly, when exhaust smoke is ejected from the safety valve 35, the impact acting on the lower protrusion 30 can be mitigated, and the exhaust smoke can be reliably guided into the lower protrusion 30.

[0061] The present invention has been described above as one embodiment, but the present invention is not limited to such an embodiment. One embodiment and various modifications can be used in combination as appropriate, and it can be implemented in various ways without departing from the spirit of the present invention.

Claims

1. A rear structure of a vehicle, wherein, The battery casing includes a lower casing that forms a receiving portion, in which multiple battery modules, arranged along the vehicle's longitudinal direction and along the vehicle's width direction, are arranged. The rear structure of the vehicle comprises: A longitudinal frame, disposed on the lower wall of the lower housing, extends along the longitudinal direction of the vehicle between the battery modules arranged along the width direction of the vehicle; and The lower protrusion is located on the lower wall of the lower housing and is positioned between adjacent longitudinal frames in the vehicle width direction. It protrudes downward toward the vehicle and is connected to the outside of the vehicle, opposite a safety valve disposed on one of the multiple battery cells constituting the battery module and capable of releasing pressure within the battery cells. The lower protrusion is provided along the front-rear direction of the vehicle for each of the battery modules and can communicate with the outside at the rear end of the battery housing.

2. The vehicle rear structure according to claim 1, wherein, The width of the lower protrusion in the vehicle width direction decreases as it moves toward the lower side of the vehicle, and the width of the lowermost end of the lower protrusion is greater than the size of the safety valve's outer dimensions along the vehicle width direction.

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