Vehicle rear structure

Abstract

Provided is a vehicle rear structure capable of discharging gas from an electricity storage device, said gas being leaked from a battery cell.　This vehicle rear structure comprises: an electricity storage device that has a plurality of battery cells; a gas exhaust valve that allows gas to flow out in one direction; a gas exhaust flow path cover that forms a part of a gas exhaust flow path by covering the upper side of the gas exhaust valve in the vehicle vertical direction; and an opening provided in a side surface of the gas exhaust flow path cover on the battery cell side.

Description

Vehicle rear structure

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

[0002] Japanese Patent No. 7259673 discloses a battery pack including a battery module having a plurality of battery cells, and a smoke exhaust channel provided below the battery cells for allowing gas discharged from the battery cells to flow therethrough.

[0003] In a battery pack, there is a small possibility that smoke leaks not only through the smoke exhaust channel provided below the battery cells but also from weakened portions of the battery cells, gaps between battery cells, and the like, and there is room for improvement in the path for discharging the leaked smoke.

[0004] One embodiment of the present disclosure has been made in view of the above circumstances, and an object thereof is to obtain a vehicle rear structure capable of discharging smoke inside a power storage device that has leaked from battery cells.

[0005] A vehicle rear structure according to a first aspect of the present disclosure includes: a power storage device having a plurality of battery cells; a smoke exhaust valve that allows unidirectional outflow of gas; a smoke exhaust channel cover that forms a part of the smoke exhaust channel by covering an upper side of the smoke exhaust valve in a vehicle vertical direction; and an opening provided on a side surface of the smoke exhaust channel cover on the battery cell side.

[0006] In the vehicle rear structure according to the first aspect of the present disclosure, since the opening is provided on the side surface of the smoke exhaust channel cover on the battery cell side, smoke inside the power storage device that has leaked from the battery cells can be discharged through the opening.

[0007] In the vehicle rear structure according to a second aspect of the present disclosure, in the configuration of the first aspect described above, the opening is in communication with the smoke exhaust channel formed by the smoke exhaust channel cover.

[0008] In the vehicle rear structure according to the second aspect of the present disclosure, since the opening is in communication with the smoke exhaust channel formed by the smoke exhaust channel cover, smoke discharged from the smoke exhaust channel and smoke leaked into the power storage device can be collected and discharged together.

[0009] In the vehicle rear structure according to a third aspect of the present disclosure, in the configuration of the first aspect or the second aspect described above, the smoke exhaust channel cover has a concave shape with an open lower side in the vehicle vertical direction.

[0010] In the vehicle rear structure according to the third aspect of this disclosure, the exhaust gas passage cover has a concave shape with the lower side in the vertical direction of the vehicle open, so that a space can be provided below the exhaust gas passage cover. This allows for more efficient exhaust of smoke.

[0011] In the vehicle rear structure according to the fourth aspect of this disclosure, in any configuration of the first to third aspects described above, the exhaust gas flow path cover is a separate component from the energy storage device.

[0012] In the rear vehicle structure according to the fourth aspect of this disclosure, the exhaust gas flow path cover and the energy storage device are made of separate parts, so by changing the shape of the exhaust gas flow path cover, the degree of design freedom for the exhaust gas flow path above the exhaust gas valve can be increased.

[0013] A vehicle rear structure according to a fifth aspect of the present disclosure further comprises a temperature detection unit provided in the exhaust gas flow path cover for detecting the air temperature inside the exhaust gas flow path, in any configuration of the first to fourth aspects described above.

[0014] In the vehicle rear structure according to the fifth aspect of this disclosure, a temperature detection unit is provided in the exhaust gas passage cover, so that the temperature in the exhaust gas passage can be detected by the temperature detection unit. This makes it possible to detect when the temperature rises in the exhaust gas passage. Furthermore, since the temperature detection unit is provided in the exhaust gas passage cover, the position of the temperature detection unit can be easily moved, which improves the degree of design flexibility.

[0015] In the sixth aspect of the present disclosure, the rear vehicle structure, in the configuration of the fifth aspect, is provided on the upper inner surface on the upstream side of the exhaust gas flow path formed by the exhaust gas flow path cover.

[0016] In the rear vehicle structure according to the sixth aspect of this disclosure, the temperature detection unit is provided on the upper surface on the upstream side of the exhaust gas flow path formed by the exhaust gas flow path cover, so that the temperature of the smoke immediately after it flows into the exhaust gas flow path cover can be detected. This allows for notification before smoke with an abnormal temperature flows into the exhaust gas valve.

[0017] In the seventh aspect of the present disclosure, the rear vehicle structure, in the configuration of the fifth or sixth aspect, is configured such that the temperature detection unit is located in a position that does not overlap with the exhaust valve when viewed from above.

[0018] As smoke flows into the exhaust valve, smoke is less likely to accumulate above the exhaust valve. In the rear vehicle structure according to the seventh aspect of this disclosure, the temperature detection unit is located in a position that does not overlap with the exhaust valve when viewed from above, so the temperature of the smoke can be detected with greater accuracy compared to the case where the temperature detection unit is located above the exhaust valve.

[0019] In the eighth aspect of the present disclosure, the rear vehicle structure, in any configuration of the fifth to seventh aspects described above, is configured such that the temperature detection unit is comprised of a smoke exhaust thermistor.

[0020] In the rear vehicle structure according to the eighth aspect of this disclosure, the temperature detection unit is composed of a smoke exhaust thermistor, which reduces costs and miniaturizes the installation space.

[0021] A rear vehicle structure according to a ninth aspect of the present disclosure comprises, in any configuration of the first to eighth aspects described above, a bus bar disposed on the rear side of the vehicle of the energy storage device, and a flow path member constituting a part of the exhaust gas flow path, wherein the exhaust gas flow path cover is disposed below the bus bar in the vertical direction of the vehicle and constitutes a part of the flow path member.

[0022] In the rear vehicle structure according to the ninth aspect of this disclosure, a smoke exhaust flow path cover, which constitutes part of the flow path member, is provided on the lower side of the busbar in the vertical direction of the vehicle. This allows the smoke exhaust flow path to be positioned below the busbar, avoiding interference with the busbar while ensuring sufficient flow path cross-sectional area.

[0023] The rear vehicle structure according to the tenth aspect of the present disclosure, in the configuration described in the ninth aspect, wherein the exhaust gas flow path cover constitutes a part of the upper side of the flow path member in the vertical direction of the vehicle.

[0024] In the vehicle rear structure according to the tenth aspect of this disclosure, the exhaust gas flow path cover constitutes a part of the upper side of the flow path member in the vertical direction of the vehicle, so that the exhaust gas flow path cover is located between the exhaust gas flow path and the busbar. This prevents the smoke from coming into contact with the busbar.

[0025] In the vehicle rear structure according to the eleventh aspect of the present disclosure, the exhaust gas flow path cover is separated from the bus bar in the configuration of the ninth or tenth aspect described above.

[0026] In the rear vehicle structure according to the eleventh aspect of this disclosure, since the exhaust duct cover is separated from the busbar, even if the heat from the smoke acts on the exhaust duct cover, it is difficult for the heat to be transferred from the exhaust duct cover to the busbar.

[0027] A vehicle rear structure according to one embodiment of this disclosure has the excellent effect of being able to discharge smoke from the battery cell inside the energy storage device.

[0028] This is a schematic plan view showing the rear vehicle structure according to this embodiment. This is a schematic perspective view showing the battery pack and smoke exhaust structure provided in the rear vehicle structure according to this embodiment. This is a schematic cross-sectional view of the rear vehicle structure of Figure 1 when cut along the longitudinal direction of the vehicle. This is a schematic cross-sectional view of the rear vehicle structure of Figure 1 when cut along the width direction of the vehicle. This is a schematic cross-sectional view of the rear vehicle structure of Figure 1 when cut along the line A-A. This is a partially enlarged cross-sectional view showing an enlarged portion of Figure 4, an enlarged perspective view showing an enlarged portion of the main part of the rear vehicle structure according to this embodiment. This is a partially enlarged detailed perspective view showing an enlarged portion of the main part of Figure 7. This is a schematic cross-sectional view of the rear vehicle structure of Figure 8 when cut along the line B-B. This is an exploded perspective view showing an enlarged portion of the main part of the rear of the battery pack shown in Figure 1.

[0029] The vehicle rear structure of the first embodiment of this disclosure will be described below with reference to the drawings. In the following description, only the extent necessary for explaining the technology of this disclosure will be described, and any parts that are omitted from the description will be based on prior art. In the drawings, identical or equivalent members are denoted by the same or similar reference numerals, and redundant explanations will be omitted. Furthermore, if there are multiple identical or equivalent members in the drawings, reference numerals may be assigned to only some of them in order to make the drawings easier to understand. In the drawings, arrows FR, UP, and LH indicate the front, up, and left directions of the vehicle 10, respectively. In the following description, unless otherwise specified, when the directions front, back, up, and left are used, they refer to the front and back in the vehicle's front-rear direction, the up and down in the vehicle's up-down direction, and the left and right in the vehicle's width direction (left-right direction), respectively.

[0030] Figure 1 is a schematic plan view partially showing an example of a vehicle 10 equipped with the vehicle rear structure 14 in this embodiment, and Figure 2 is a schematic perspective view showing the battery pack 18 and smoke exhaust structure 16 mounted on the vehicle 10. Note that the upper cover 26, which will be described later, is not shown in Figures 1 and 2.

[0031] As shown in Figure 1, the vehicle 10 is equipped with a battery pack 18 as an energy storage device. As also shown in Figure 2, the battery pack 18 has a plurality of (four in this embodiment) battery modules 20. The plurality of battery modules 20 are arranged in a line in the vehicle width direction. A gap GP5 is formed between the battery modules 20. In this embodiment, since there are four battery modules 20, there are three gaps GP5 formed between these battery modules 20.

[0032] Each of the battery modules 20 has multiple battery cells 22. The multiple battery cells 22 are arranged in a row in the vehicle's longitudinal direction within the battery module 20. That is, the battery pack 18 is configured such that multiple battery modules 20, each having multiple battery cells 22 arranged in the vehicle's longitudinal direction, are arranged in a row in the vehicle's width direction.

[0033] Figure 3 is a cross-sectional view of the vehicle rear structure 14 shown in Figure 1 when cut along the longitudinal direction of the vehicle, and Figure 4 is a cross-sectional view of the vehicle rear structure 14 shown in Figure 1 when cut along the vehicle width direction. Figure 5 is a schematic cross-sectional view of the vehicle rear structure of Figure 1 when cut along the line A-A.

[0034] As shown in Figures 3 to 5, the battery pack 18 has a lower case 24 and an upper cover 26. The lower case 24 is a box-shaped member capable of housing the battery module 20 and is composed of a bottom plate 24L, a front plate 24F, a rear plate 24R, and a pair of left and right side plates 24S. The bottom 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 erected from the front and rear sides of the bottom plate 24L, respectively. The side plates 24S are plate-shaped portions erected from both sides of the bottom plate 24L in the vehicle width direction. The top surface of the lower case 24 is open, and as shown in Figure 3, flange portions 25 protrude outward from the periphery of the lower case 24.

[0035] The upper cover 26 is a lid-shaped member that covers the top surface of the lower case 24. The periphery of the lower case 24 and the periphery of the upper cover 26 are joined together, and the lower case 24 and the upper cover 26 together constitute a battery case 28. Multiple battery modules 20, each composed of multiple battery cells 22, are housed in the space inside this battery case 28, arranged in the vehicle width direction.

[0036] A share panel 46 is positioned on the underside of the battery pack 18. In this embodiment, the share panel 46 covers the underside of the battery pack 18 and protects the battery module 20 from foreign objects on the road surface.

[0037] As shown in Figure 5, an equipment case 31 is positioned above the rear end of the upper cover 26. Inside the equipment case 31 are a junction box 33 (control device) containing relays, auxiliary equipment, etc., an ECU (control device) 35, etc. The relays and auxiliary equipment are connected to the battery module 20 by wiring conduits 88 (see Figure 7), such as wire harnesses, which will be described later, and are electrically connected to the battery module 20.

[0038] Furthermore, an opening 27 (see Figure 10) is formed at the rear end of the upper cover 26. Through this opening 27, the internal space 37 of the equipment case 31 shown in Figure 5 and the inside of the battery pack 18 are in communication.

[0039] Figure 6 is a partially enlarged cross-sectional view showing an enlarged portion of Figure 4, and Figure 7 is an enlarged perspective view showing an enlarged portion of the main part of the vehicle rear structure 14 according to this embodiment, and shows a perspective view of the rear plate 24R side of the lower case 24.

[0040] As shown in Figures 6 and 7, the lower plate 24L of the lower case 24 is bonded to the lower surface of each battery cell 22 with adhesive. Multiple downward protrusions 30 (the same number as the battery module 20) are formed on the lower plate 24L. The downward protrusions 30 protrude downward at the central position in the vehicle width direction of each battery module 20. In other words, at the downward protrusions 30, the lower case 24 is partially separated from the lower surface of the battery cell 22, forming a gap GP1.

[0041] Furthermore, the lower protrusions 30 are formed to extend in the vehicle longitudinal direction, that is, in the direction in which the battery cells 22 are arranged, in each of the battery modules 20. The length of the lower protrusions 30 in the vehicle longitudinal direction is approximately the same as the length of the battery module 20 in the vehicle longitudinal direction, and they extend continuously in the vehicle longitudinal direction from the vicinity of the front plate 24F to the vicinity of the rear plate 24R.

[0042] As described above, the gap GP1 spaced apart from the lower surface of the storage battery cell 22 by the lower convex portion 30 extends in the vehicle front-rear direction, whereby the gap GP1 constitutes a part of the smoke exhaust flow path 32. In the storage battery cell 22, when gas containing smoke (hereinafter, this gas is simply referred to as "smoke") is generated for some reason, the smoke is discharged from a central position in the vehicle width direction on the lower surface of the storage battery cell 22. Therefore, the smoke generated in the storage battery cell 22 flows into the gap GP1 formed by the lower convex portion 30. The lower case 24 formed with the lower convex portion 30 is a part of the flow path member constituting the smoke exhaust flow path 32. As will be described later, the smoke exhaust flow path 32 is continuously provided from the gap GP1 to GP4, so that the generated smoke is efficiently guided to the smoke exhaust valve 52.

[0043] On the other hand, as shown in FIG. 6, the lower case 24 is provided with a cooler 38 along the vehicle front-rear direction. The coolers 38 are respectively provided on both sides of the lower convex portion 30 in the vehicle width direction on the lower surface of the lower case 24, and constitute a refrigerant flow path extending in the vehicle front-rear direction. Heat of the cooler 38 is transferred to the refrigerant flowing through the refrigerant flow path, whereby the storage battery cell 22 is cooled, and overheating of the storage battery cell 22 can be suppressed.

[0044] As shown in FIGS. 1, 2, 4 and 6, a reinforcing member 40 is disposed in each of the gaps GP5 between the storage battery modules 20. As shown in FIG. 6, when viewed in a cross-section in the vehicle width direction, the reinforcing member 40 has a substantially hat-shaped cross-sectional shape with an open lower side.

[0045] As shown in FIG. 1, the reinforcing member 40 has a length that reaches the vicinity of a front plate 24F and a rear plate 24R of the lower case 24. A front end 40A and a rear end 40B of the reinforcing member 40 are respectively joined to the front plate 24F and the rear plate 24R of the lower case 24 by joining members 42. Thereby, the reinforcing member 40 reinforces the storage battery pack 18.

[0046] As shown in FIGS. 5 and 7, the bonding member 42 has a first spaced portion 42D spaced apart from the rear plate 24R of the lower case 24 between a bonding surface 42A in surface contact with the lower plate 24L of the lower case 24 and a bonding surface 42B in surface contact with the rear plate 24R of the lower case 24. The first spaced portion 42D is formed obliquely when viewed in a cross-section in the vehicle front-rear direction, and a gap GP2 is formed between the first spaced portion 42D and the lower case 24. This gap GP2 is continuous in the vehicle width direction and communicates with a gap GP1 formed by the lower surface of the storage battery cell 22 and the downward convex portion 30. That is, this gap GP2 forms a part of the smoke exhaust flow path 32. Further, the bonding member 42 is a part of the flow path member constituting the smoke exhaust flow path 32.

[0047] On the other hand, as shown in FIG. 6, a cell pedestal 44 is formed on the lower plate 24L of the lower case 24 at a position corresponding to the reinforcing member 40. The cell pedestal 44 is a portion where the lower plate 24L of the lower case 24 is formed to protrude downward at a position corresponding to the reinforcing member 40. The cell pedestal 44 is bonded to the reinforcing member 40 and closes the open portion on the lower side of the reinforcing member 40.

[0048] A front end 40A and a rear end 40B of the reinforcing member 40 are open (see FIG. 1) and communicate with the gap GP2 shown in FIG. 5. That is, the portion of the closed cross-sectional shape (shape closed in a cross-section in the vehicle width direction) constituted by the reinforcing member 40 and the cell pedestal 44 communicates with the smoke exhaust flow path 32 constituted by the gap GP2. Accordingly, the closed cross-sectional shape constituted by the reinforcing member 40 and the cell pedestal 44 also forms a part of the smoke exhaust flow path 32. That is, the reinforcing member 40 and the cell pedestal 44 are a part of the flow path member.

[0049] In the present embodiment, a part of the lower case 24 also serves as the cell pedestal 44. That is, the structure is such that the lower case 24, which also serves as the cell pedestal 44, extends across the plurality of reinforcing members 40. In other words, with respect to the plurality of reinforcing members 40, the cell pedestals 44 are integrally provided by the lower case 24, thereby forming a part of the smoke exhaust flow path 32.

[0050] Furthermore, as shown in Figure 1, a connector block 50 is positioned on the rear side of the lower case 24. The front edge (the side facing the front of the vehicle) of the connector block 50 is straight in the direction of the vehicle width. In contrast, the rear edge (the side facing the rear of the vehicle) of the connector block 50 is curved such that its center in the direction of the vehicle width is convex toward the rear of the vehicle. Therefore, the central part 50C of the connector block 50 in the direction of the vehicle width is longer in the vehicle-rear direction than both ends 50E in the vehicle-width direction.

[0051] Furthermore, as shown in Figures 1 and 5, a smoke exhaust valve 52 is attached to the connector block 50. A cover plate 54 is attached to the connector block 50, which serves as a smoke exhaust flow path cover that forms a smoke exhaust flow path 32 between the battery pack 18 and the smoke exhaust valve 52. The cover plate 54 is a separate part from the battery case 28.

[0052] Figure 8 is an enlarged and detailed perspective view of a key part of Figure 7, showing a perspective view of the area around the cover plate 54. Figure 9 is a schematic cross-sectional view of the vehicle rear structure 14 in Figure 8 when cut along the line B-B.

[0053] As shown in Figures 7 to 9, the cover plate 54 has an upper protrusion 58 formed thereon. The upper protrusion 58 has a shape in which the central part in the vehicle width direction is curved upward on the front side of the vehicle. In other words, the cover plate 54 has a concave shape with the bottom open. As shown in Figures 8 and 9, the upper protrusion 58 specifically includes, as an example, a rear upper protrusion 58A located on the rear side and formed in a substantially rectangular shape when viewed from above, and a front upper protrusion 58B extending diagonally forward and upward from the front end of the rear upper protrusion 58A and formed in a substantially rectangular shape when viewed from above.

[0054] The rear upper protrusion 58A is formed with its rear end and peripheral edges on both sides extending diagonally inward and upward from the flat portion 54A of the cover plate 54. As shown in Figure 8, this flat portion 54A is fixed to the upper surface 50A of the connector block 50 by fastening members BT such as bolts. Furthermore, as shown in Figure 9, the rear upper protrusion 58A covers the upper side of the smoke exhaust valve 52, forming a gap GP4-A between it and the smoke exhaust valve 52. In other words, the rear upper protrusion 58A of the cover plate 54 covers the upper side of the smoke exhaust valve 52, thereby forming the portion of the smoke exhaust passage 32 on the smoke exhaust valve 52 side.

[0055] Furthermore, since the lower surface of the flat portion 54A at the rear end of the cover plate 54 is in contact with the upper surface 50A of the connector block 50, the rear end of the gap GP4-A is closed, and the smoke exhaust passage 32 is also closed. In other words, the smoke exhaust valve 52 is provided at the downstream end of the smoke exhaust passage 32.

[0056] The upper surface of the front upper protrusion 58B is located above the upper surface of the rear upper protrusion 58A, and the peripheral edges of both ends are fixed to the flange portion 25 by fastening members BT such as bolts. As described above, the rear end of the front upper protrusion 58B is connected to the front end of the rear upper protrusion 58A. On the other hand, the front end of the front upper protrusion 58B is open toward the front. Furthermore, as shown in Figure 9, the front end of the front upper protrusion 58B is located in front of the smoke exhaust valve 52, and is arranged so that its front end extends forward of the front end of the connector block 50. Also, as an example, the front end of the front upper protrusion 58B is arranged to be located in front of the second separation portion 42E, which will be described later.

[0057] Furthermore, as shown in Figure 9, the front upper protrusion 58B covers the upper side of the gap GP2, forming a gap GP4-B between it and the lower case 24 and the connector block 50, and the gap GP2 and the gap GP4-B are in communication. In other words, the front upper protrusion 58B of the cover plate 54 covers the upper side of the lower case 24 and the connector block 50, thereby forming the portion of the smoke exhaust passage 32 on the battery cell 22 side.

[0058] Furthermore, as shown in Figure 8, the cover plate 54 has an opening 59 on the side of the front upper protrusion 58B that faces the battery cell 22. The opening 59 is provided to communicate with the open portion at the front end of the front upper protrusion 58B and extends to the upper surface of the front upper protrusion 58B. In other words, the opening 59 is formed by cutting out the upper surface of the front upper protrusion 58B from the front end to the rear side of the center of the upper surface. For example, the opening 59 is provided from the center of the front upper protrusion 58B in the vehicle width direction toward the left, and is formed to become narrower toward the rear. The rear end of the opening 59 is also formed in an arc shape.

[0059] As shown in Figure 9, the opening 59 is in communication with the smoke exhaust passage 32 formed by the cover plate 54, namely the gaps GP4-A and GP4-B. The gaps GP4-A and GP4-B together constitute the gap GP4 formed between the cover plate 54 and the lower case 24. This gap GP4 allows smoke to move in the longitudinal direction of the vehicle and forms part of the smoke exhaust passage 32. In other words, the cover plate 54 is part of the flow path member that constitutes the smoke exhaust passage 32, and specifically the cover plate 54 constitutes part of the upper side of the flow path member.

[0060] Furthermore, the cover plate 54 has an elongated hole 54B in the vehicle width direction, located in the center of the vehicle's front-rear direction, to the right of the opening 59 of the front upper protrusion 58B. As shown in Figure 9, a smoke exhaust thermistor 60, which serves as a temperature detection unit, is mounted in this elongated hole 54B. The smoke exhaust thermistor 60 detects the temperature inside the smoke exhaust passage 32. The smoke exhaust thermistor 60 is disposed within the smoke exhaust passage 32 formed by the cover plate 54, specifically within the gap GP4-B. That is, the smoke exhaust thermistor 60 is located on the inner upper surface 54C on the upstream side of the smoke exhaust passage 32 formed by the cover plate 54. Also, the smoke exhaust thermistor 60 is located in a position that does not overlap with the smoke exhaust valve 52 when viewed from above. Note that the temperature detection unit is not limited to the smoke exhaust thermistor 60; any device capable of detecting the temperature inside the smoke exhaust passage 32 may be used, such as a thermometer.

[0061] As shown in Figure 7, of the two connecting members 42, the connecting member 42 located on the rear side of the vehicle is provided with a second separation portion 42E. The second separation portion 42E is formed at a position corresponding to the upper protrusion 58 in the vehicle width direction. A gap GP3 is formed between the second separation portion 42E and the rear plate 24R of the lower case 24. Therefore, the exhaust gas flow path 32 in the battery pack 18 is formed to be continuous from the gap GP1 between the lower surface of the battery cell 22 and the lower protrusion 30, through the gaps GP2 and GP3 between the connecting member 42 and the lower case 24, and the gap GP4 between the cover plate 54 and the lower case 24, all the way to the exhaust gas valve 52.

[0062] The smoke exhaust valve 52 is configured to open when the internal pressure of the smoke exhaust passage 32 becomes higher than the external air pressure of the smoke exhaust passage 32 by a predetermined value or more. In other words, when smoke flows into the smoke exhaust passage 32 and the internal pressure rises above a predetermined value, the smoke exhaust valve 52 opens, and the gas inside the smoke exhaust passage 32 is discharged to the outside.

[0063] Furthermore, a breathing membrane 56 is attached to the connector block 50. The breathing membrane 56 is designed to allow gas to pass through but to block the passage of liquid (including steam). For example, Gore-Tex® is used as the material. In addition, even when gas is permeable, it is designed to resist the movement of gas so that the gas does not move rapidly in a short period of time. In this embodiment, the breathing membrane 56 is provided at a position outside the vehicle width direction of the smoke exhaust valve 52.

[0064] On the other hand, as shown in Figure 7, the lower surface of the connector block 50, including the central part in the vehicle width direction, is equipped with, for example, a first resin connector 62, a second resin connector 64, and a third metal connector 66. Although not shown in the figure, wiring is connected to each of these connectors. Of these connectors, the first connector 62 is located on the side of the smoke exhaust valve 52, while the second connector 64 and the third connector 66 are located on the opposite side of the smoke exhaust valve 52, with the first connector 62 in between.

[0065] Furthermore, as shown in Figures 1 and 7, the connector block 50 is provided with a smoke exhaust valve 52 and a breathing membrane 56 on its outer side in the vehicle width direction, but a cable routing block 80 is formed on the rearward side of the vehicle from the smoke exhaust valve 52 and breathing membrane 56. This cable routing block 80 is erected from the upper surface 50A of the connector block 50 and is a flattened cylindrical shape in the front-rear direction of the vehicle.

[0066] Specifically, the cable routing block 80 is shaped to be longer in the vehicle width direction than in the vehicle front-to-rear direction when viewed from above the vehicle, and is provided on the outer edge side of the connector block 50. Furthermore, when viewed from the outside of the vehicle, the cable routing block has a roughly frustoconical shape, and the cross-sectional shape when cut horizontally becomes larger towards the lower side of the vehicle.

[0067] Furthermore, a circular first insertion hole 80A and a second insertion hole 80B are formed inside the cable routing block 80, penetrating the connector block 50 in the vertical direction. In this embodiment, there are two first insertion holes 80A, and there is one second insertion hole 80B, which is larger in diameter than the first insertion holes 80A. The second insertion hole 80B is also located further outward in the vehicle width direction than the first insertion holes 80A. The two first insertion holes 80A are spaced apart in the vehicle width direction, and the second insertion hole 80B is also spaced apart from the first insertion holes 80A in the vehicle width direction.

[0068] For example, a circulation pipe 86 for circulating cooling water to the vehicle's mounted equipment is inserted through the first insertion hole 80A. A wiring pipe 88 containing multiple wires for sending electrical signals to the mounted equipment is inserted through the second insertion hole 80B. The circulation pipe 86 and the wiring pipe 88 are examples of wiring members routed to the vehicle. In other words, in this embodiment, a plurality of wiring members spaced apart from each other in the vehicle width direction are inserted into the wiring block 80 along the vertical direction.

[0069] On the other hand, as shown in Figure 9, in the vehicle rear structure 14, a bus bar 70 is positioned on the rear side of the battery case 28. Specifically, the bus bar 70 is positioned above the cover plate 54. In other words, the bus bar 70 is positioned below the cover plate 54. In this embodiment, the cover plate 54 is spaced apart from the bus bar 70.

[0070] Here, the busbar 70 will be described. Figure 10 is an exploded perspective view showing an enlarged view of the main rear part of the battery pack 18 shown in Figure 1. As shown in Figure 10, the busbar 70 includes a positive busbar 72 and a negative busbar 74 that are electrically connected to a plurality of battery modules 20. The battery module 20 consists of a plurality of battery cells 22 arranged in a row along the front-to-back direction, end plates 22A disposed at both ends in the front-to-back direction to support the plurality of battery cells 22, and a support 20A that supports the plurality of battery cells 22 and the end plates 22A. The end plates 22A are provided with one terminal 20B each that constitutes the positive and negative terminals of the battery module 20.

[0071] The lower case 24 is divided into a module installation area 24A on which multiple battery modules 20 are mounted, and a busbar arrangement area 24B on which the positive busbar 72 and negative busbar 74 are arranged. The module installation area 24A is composed of a rectangular area that conforms to the shape of the multiple battery modules 20. The busbar arrangement area 24B is composed of an area that is narrowed towards the rear so as to ensure space for routing the positive busbar 72 and negative busbar 74, while not interfering with the rear wheels of the vehicle on which the battery pack 18 is mounted.

[0072] The polarity of the terminals 20B at both ends in the front-rear direction of each of the multiple battery modules 20 installed in the module installation area 24A can be adjusted to match the connection configuration between the battery modules 20. In this embodiment, as an example, the terminals 20B of adjacent battery modules 20 are arranged to have different polarities on the front and rear sides.

[0073] Furthermore, an equipment case 31 (see Figure 5) is positioned at the rear upper part of the upper cover 26 such that at least a portion of it overlaps with the positive busbar 72 and the negative busbar 74 in a plan view. A portion of the upper cover 26 corresponding to the busbar arrangement area 24B is provided with an opening 27 that penetrates vertically and electrically connects the equipment case 31 and the battery module 20. Note that the equipment case 31 is not shown in Figure 10.

[0074] The positive electrode busbar 72 is connected to the positive electrodes of multiple battery modules 20 and is led out to the busbar installation area 24B. The positive electrode busbar 72 constitutes part of the wiring for connecting the multiple battery modules 20 to the electrical equipment inside the equipment case 31 and may be made of a strip-shaped metal plate. The positive electrode busbar 72 in this embodiment has contacts (not shown) at both ends, and one contact is electrically connected to a terminal 20B provided on the rear end plate 22A on one end in the left-right direction of the multiple battery modules 20 that are electrically connected to each other. In addition, the part of the positive electrode busbar 72 other than the contacts is covered by an insulating cover (not shown). Copper, aluminum, brass, or alloys thereof may be used for the various busbars, including the positive electrode busbar 72 used in this embodiment.

[0075] The negative electrode busbar 74 is connected to the negative electrodes of multiple battery modules 20 and is led out to the busbar installation area 24B. Like the positive electrode busbar 72, this negative electrode busbar 74 also constitutes part of the wiring for connecting the multiple battery modules 20 to the electrical equipment inside the equipment case 31 and may be made of a strip-shaped metal plate. The negative electrode busbar 74 in this embodiment has contacts (not shown) at both ends, and one contact is electrically connected to a terminal 20B provided on the rear end plate 22A on the other end in the left-right direction of the multiple battery modules 20 that are electrically connected to each other. The part of the negative electrode busbar 74 other than the contacts is covered by an insulating cover (not shown).

[0076] By arranging the positive busbar 72 and negative busbar 74 behind the multiple battery modules 20, the wiring space for each busbar can be consolidated at the rear of the battery modules 20. This configuration eliminates the need to secure space for the positive busbar 72 and negative busbar 74 in the module installation area 24A of the lower case 24, thus allowing for a more compact installation space for the battery modules 20. Furthermore, the consolidated arrangement of the positive busbar 72 and negative busbar 74 simplifies assembly work, including connection between the positive busbar 72 and negative busbar 74 and electrical equipment inside the equipment case 31. The positive busbar 72 and negative busbar 74 are fixed to the lower case 24 and upper cover 26, etc., by fastening means such as bolts (not shown).

[0077] Furthermore, in order to enable partial charging and discharging of the multiple battery modules 20, the battery pack 18 has a pair of neutral point busbars 76 and 78 connected to the neutral points of the multiple battery modules 20 which are electrically connected to each other. The pair of neutral point busbars 76 and 78 in this embodiment are led out behind the multiple battery modules 20 and arranged in the busbar arrangement area 24B, similar to the positive electrode busbar 72 and the negative electrode busbar 74. The neutral point refers to the midpoint or voltage reference point that divides the voltage of the multiple electrically connected battery modules into two equal parts.

[0078] The neutral busbars 76 and 78, like the positive busbar 72 and negative busbar 74, constitute wiring for connecting the multiple battery modules 20 to the electrical equipment inside the equipment case 31, and may be made of, for example, a strip of metal plate. The neutral busbars 76 and 78 are each provided with contacts (not shown) at both ends. One contact of each of the neutral busbars 76 and 78 is connected to the neutral point of the multiple electrically connected battery modules 20. For example, one contact of one neutral busbar 76 is electrically connected to a terminal 20B provided on the rear end plate 22A of the battery module 20. Similarly, one contact of the other neutral busbar 78 is electrically connected to a terminal 20B provided on the rear end plate 22A of the battery module 20. The parts of the pair of neutral busbars 76 and 78 excluding the contacts are each covered by an insulating cover (not shown). The polarity of terminal 20B to which the pair of neutral busbars 76 and 78 are connected is not particularly limited, but for example, the polarity of each terminal 20B is adjusted so that one neutral busbar 76 is the negative terminal and the other neutral busbar 78 is the positive terminal.

[0079] The other contacts (not shown) of the aforementioned busbars are connected to electrical equipment inside the equipment case 31. However, if each busbar were to be directly routed to the electrical equipment inside the equipment case 31, the total length of each busbar would become long, potentially making handling and management difficult. Therefore, in this embodiment, the other contact (not shown) of the positive busbar 72 is connected to terminal block 72A, and similarly, the other contact (not shown) of the negative busbar 74 is connected to terminal block 74A, the other contact (not shown) of one neutral busbar 76 is connected to terminal block 76A, and the other contact (not shown) of the other neutral busbar 78 is connected to terminal block 78A. The positive busbar 72, the negative busbar 74, and the pair of neutral busbars 76 and 78 are then connected to the electrical equipment inside the equipment case 31 via these terminal blocks 72A, 74A, 76A, and 78A. In Figure 10, among these terminal blocks 72A, 74A, 76A, and 78A, terminal block 74A to which the other contact of the negative busbar 74 (not shown) is connected, and terminal block 78A to which the other contact of the other neutral busbar 78 (not shown) is connected, are positioned in a location hidden by other components.

[0080] The battery pack 18 includes a positive terminal busbar 31A, a negative terminal busbar 31B, and two neutral terminal busbars 31C and 31D, one end of which is connected to the terminal blocks 72A, 74A, 76A, and 78A described above. The positive terminal busbar 31A, the negative terminal busbar 31B, and the two neutral terminal busbars 31C and 31D can be made of strip-shaped metal plates arranged behind the electrical equipment inside the equipment case 31. The other ends of the positive terminal busbar 31A, the negative terminal busbar 31B, and the two neutral terminal busbars 31C and 31D are electrically connected to the electrical equipment inside the equipment case 31, more specifically to the junction box 33 (see Figure 5).

[0081] The equipment-side positive busbar 31A is electrically connected to the positive busbar 72 via terminal block 72A, the equipment-side negative busbar 31B is electrically connected to the negative busbar 74 via terminal block 74A, and the two equipment-side neutral busbars 76 and 78 are electrically connected to each other via terminal blocks 76A and 78A, respectively. Furthermore, terminal blocks 72A, 74A, 76A, and 78A are arranged, for example, in a position that overlaps the opening 27 in a plan view, in order to enable connections to the equipment-side positive busbar 31A, the equipment-side negative busbar 31B, and the two equipment-side neutral busbars 31C and 31D over a short distance and to facilitate the connection work.

[0082] By using the terminal blocks 72A, 74A, 76A, and 78A described above, the overall length of each busbar can be shortened, making it easier to handle the busbars. In addition, the connection between the terminal blocks 72A, 74A, 76A, and 78A and the equipment-side positive busbar 31A, equipment-side negative busbar 31B, and the two equipment-side neutral busbars 31C and 31D can be performed at the same time that the electrical equipment inside the equipment case 31 is attached to the top of the upper cover 26 of the battery case 28, thus simplifying the assembly process.

[0083] Next, the operation and effects of this embodiment will be described.

[0084] In a vehicle 10 to which the rear vehicle structure 14 of this embodiment is applied, a battery module 20 is composed of multiple battery cells 22. That is, multiple battery cells 22 can be integrally configured by the battery module 20.

[0085] The battery cells 22 are arranged in a row in the vehicle's longitudinal direction within the battery module 20, and the battery module 20 is further arranged in a row in the vehicle's width direction. This allows for the efficient arrangement of multiple battery cells 22 in both the vehicle's longitudinal and vehicle width directions. In particular, since the arrangement direction of the battery cells 22 in the battery module 20 is in the vehicle's longitudinal direction, the number of battery cells 22 per row can be increased compared to a configuration in which the battery cells 22 are arranged in the vehicle's width direction.

[0086] In the battery cell 22, smoke is not normally generated, but if smoke is generated for any reason, the smoke is discharged from the center of the vehicle width direction on the underside of the battery cell 22. This smoke flows out into the gap GP1 provided between the lower protrusion 30 of the lower case 24 of the battery pack 18 and the underside of the battery cell 22. Furthermore, this smoke flows through the gaps GP2 and GP3 provided on the rear plate 24R side of the lower case 24, and through the gap GP4 provided between the cover plate 54 and the connector block 50 at the rear end of the lower case 24, before reaching the smoke exhaust valve 52. Gaps GP1 to GP4 each constitute part of the smoke exhaust passage 32, and when the pressure inside the smoke exhaust passage 32 becomes higher than the pressure outside, this smoke is discharged from the smoke exhaust valve 52.

[0087] Furthermore, the rear vehicle structure 14 of this embodiment has a breathing membrane 56. The breathing membrane 56 allows the movement of gas in the exhaust gas passage 32 but prevents the movement of liquid. For example, if the vehicle 10 is moved to a location with a different atmospheric pressure (for example, to a high altitude), the pressure difference between the internal pressure of the exhaust gas passage 32 and the outside atmospheric pressure will increase. In this case, this pressure difference can be mitigated by allowing air to pass through the breathing membrane 56.

[0088] Furthermore, in the vehicle rear structure 14 of this embodiment, a cover plate 54 is provided that covers the upper side of the smoke exhaust valve 52 in the vehicle vertical direction, thereby forming the portion of the smoke exhaust passage 32 on the smoke exhaust valve 52 side, and an opening 59 is provided on the side of this cover plate 54 on the battery cell 22 side. Therefore, smoke leaking from the battery cell 22 into the battery pack 18 can be discharged through the opening 59. That is, as shown by the dotted arrow in Figure 9 as an example, smoke leaking from the battery cell 22 into the battery pack 18 can be allowed to flow into the gap GP4 through the opening 59 and discharged from the smoke exhaust valve 52.

[0089] Furthermore, in the vehicle rear structure 14 of this embodiment, the opening 59 is in communication with the smoke exhaust passage 32 formed by the cover plate 54, so that smoke discharged from the smoke exhaust passage 32 and smoke leaking into the battery pack 18 can be collected and discharged. That is, as shown in Figure 9, smoke flowing from gap GP2 into gap GP4 and smoke flowing from opening 59 into gap GP4 can be collected and discharged from smoke exhaust valve 52.

[0090] Furthermore, in the vehicle rear structure 14 of this embodiment, the cover plate 54 has a concave shape with the lower side in the vertical direction of the vehicle open, so a space can be provided below the cover plate 54. This allows for more efficient exhaust of smoke. Also, in this embodiment, since the cover plate 54 has a rear upper protrusion 58A and a front upper protrusion 58B, the diameter of the smoke exhaust passage 32 is smaller in the gap GP4-A on the rear side of the vehicle than in the gap GP4-B on the front side of the vehicle. Therefore, the flow pressure of the smoke can be increased from the gap GP4-B to GP4-A, so that smoke can be efficiently discharged from the smoke exhaust valve 52.

[0091] Furthermore, in the vehicle rear structure 14 of this embodiment, the cover plate 54 and the battery pack 18 are made of separate parts, so by changing the shape of the cover plate 54, the degree of design freedom for the smoke exhaust passage 32 above the smoke exhaust valve 52 can be increased.

[0092] Furthermore, in the rear vehicle structure 14 of this embodiment, a smoke exhaust thermistor 60 is provided on the cover plate 54, so the temperature in the smoke exhaust passage 32 can be detected by the smoke exhaust thermistor 60. This allows for detection when the temperature rises in the smoke exhaust passage 32. Also, since the smoke exhaust thermistor 60 is provided on the cover plate 54, the position of the smoke exhaust thermistor 60 can be easily moved, improving the design flexibility.

[0093] Furthermore, in the rear vehicle structure 14 of this embodiment, the exhaust thermistor 60 is provided on the inner upper surface 54C on the upstream side of the exhaust flow path 32 formed by the cover plate 54, so that the temperature of the smoke immediately after it flows into the cover plate 54 can be detected. This allows for notification before smoke with an abnormal temperature flows into the exhaust valve 52.

[0094] Furthermore, because smoke flows into the smoke exhaust valve 52, smoke is less likely to accumulate above the smoke exhaust valve 52. In the rear vehicle structure 14 of this embodiment, the smoke exhaust thermistor 60 is provided in a position that does not overlap with the smoke exhaust valve 52 when viewed from above, so the smoke temperature can be detected with greater accuracy compared to the case where the smoke exhaust thermistor 60 is placed above the smoke exhaust valve 52.

[0095] Furthermore, in the vehicle rear structure 14 of this embodiment, a smoke exhaust thermistor is used as the temperature detection unit, which reduces costs and miniaturizes the installation space.

[0096] Furthermore, in the vehicle rear structure 14 of this embodiment, a cover plate 54 that constitutes part of the flow path member is provided on the lower side of the bus bar 70 in the vertical direction of the vehicle. Therefore, the exhaust gas flow path 32 can be positioned below the bus bar 70 while avoiding interference with the bus bar 70 and ensuring sufficient flow path cross-sectional area.

[0097] Furthermore, in the vehicle rear structure 14 of this embodiment, the cover plate 54 constitutes a part of the upper side of the flow path member in the vehicle's vertical direction, so the cover plate 54 is located between the exhaust gas flow path 32 and the bus bar 70. As a result, the cover plate 54 can prevent smoke from coming into contact with the bus bar 70.

[0098] Furthermore, in the vehicle rear structure 14 of this embodiment, since the cover plate 54 is separated from the bus bar 70, even if the heat from the smoke acts on the cover plate 54, it is difficult for the heat to be transferred from the cover plate 54 to the bus bar 70.

[0099] Furthermore, some of the components of this embodiment described above can be omitted or modified.

[0100] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above, and it is of course possible to implement it in various other forms without departing from its spirit.

[0101] Furthermore, the disclosure of Japanese Patent Application No. 2025-052178, filed on 26 March 2025, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A rear vehicle structure comprising: an energy storage device having multiple battery cells; a smoke exhaust valve that allows gas to flow out in one direction; a smoke exhaust passage cover that covers the upper side of the smoke exhaust valve in the vertical direction of the vehicle, thereby forming a part of the smoke exhaust passage; and an opening provided on the side of the smoke exhaust passage cover on the side facing the battery cells.

2. The rear vehicle structure according to claim 1, wherein the opening is in communication with the exhaust gas passage formed by the exhaust gas passage cover.

3. The rear vehicle structure according to claim 1, wherein the exhaust gas flow path cover has a concave shape with the lower side in the vertical direction of the vehicle open.

4. The rear vehicle structure according to claim 1, wherein the exhaust gas flow path cover is a separate component from the energy storage device.

5. The rear vehicle structure according to claim 1, further comprising a temperature detection unit provided in the exhaust gas flow path cover for detecting the temperature inside the exhaust gas flow path.

6. The vehicle rear structure according to claim 5, wherein the temperature detection unit is provided on the inner upper surface on the upstream side of the exhaust gas flow path formed by the exhaust gas flow path cover.

7. The vehicle rear structure according to claim 5, wherein the temperature detection unit is provided in a position that does not overlap with the exhaust valve when viewed from above.

8. The vehicle rear structure according to claim 5, wherein the temperature detection unit is configured with a smoke exhaust thermistor.

9. The rear vehicle structure according to claim 1, comprising a bus bar disposed on the rear side of the vehicle of the energy storage device, and a flow path member constituting a part of the exhaust gas flow path, wherein the exhaust gas flow path cover is disposed below the bus bar in the vertical direction of the vehicle and constitutes a part of the flow path member.

10. The rear vehicle structure according to claim 9, wherein the exhaust gas flow path cover constitutes a part of the upper side of the flow path member in the vertical direction of the vehicle.

11. The rear vehicle structure according to claim 9, wherein the exhaust gas flow path cover is separated from the bus bar.

Images