Vehicle rear structure

Abstract

Provided is a vehicle rear structure capable of suppressing the occurrence of a submarine phenomenon.　The vehicle rear structure comprises: a battery pack in which one or more battery cells are housed; a seat which is disposed on an upper side in a vehicle vertical direction of a vehicle rear part of the battery pack; and a support member which is disposed on a lower side in the vehicle vertical direction of the seat and on an upper side in the vehicle vertical direction of the battery pack in a position overlapping the seat in a top view, and which supports a first device on an upper surface thereof.

Description

Vehicle rear structure

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

[0002] Japanese Unexamined Patent Publication No. 2013-023219 discloses a vehicle equipped with a battery pack in which a plurality of battery cells are combined in series or parallel and housed in a battery case.

[0003] Incidentally, in the event of a frontal collision, the submarine phenomenon, in which an occupant breaks free from the restraint of a seatbelt, slides off the seat, and slips under a dashboard, under a front seat, or the like, has been a problem. Even in a vehicle equipped with a battery pack as described in Japanese Unexamined Patent Publication No. 2013-023219, there is room for improvement in terms of countermeasures against the submarine phenomenon at the time of a frontal collision.

[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 suppressing the occurrence of the submarine phenomenon.

[0005] A vehicle rear structure according to a first aspect of the present disclosure includes: a power storage device in which one or more battery cells are housed; a seat disposed at an upper side in a vehicle vertical direction of a vehicle rear portion of the power storage device; and a support member disposed at a position overlapping the seat in a top view, on a lower side in the vehicle vertical direction of the seat and on an upper side in the vehicle vertical direction of the power storage device, and supporting a first device on an upper surface thereof.

[0006] In the vehicle rear structure according to the first aspect of the present disclosure, the support member is provided at a position overlapping the seat in a top view, on the lower side in the vehicle vertical direction of the seat and on the upper side in the vehicle vertical direction of the power storage device. Therefore, the support member can prevent the seat from sinking during a frontal collision. This suppresses sinking of the hip point, and can increase the restraining force of the seatbelt on an occupant during a frontal collision, thereby suppressing the occurrence of the submarine phenomenon.

[0007] In a vehicle rear structure according to a second aspect of the present disclosure, in the configuration of the first aspect described above, the support member supports the first device on an upper surface on a front side in a vehicle front-rear direction.

[0008] In the vehicle rear structure according to a second aspect of this disclosure, the first device is supported on the upper surface of the support member on the front side in the longitudinal direction of the vehicle. As a result, the front end of the seat can be lifted by the first device, which can suppress the forward movement of occupants seated in the seat during a frontal collision, and can further suppress the occurrence of the submarine effect.

[0009] A vehicle rear structure according to a third aspect of the present disclosure, in the configuration of the first or second aspect described above, further comprises a lower support member disposed on the upper surface of the energy storage device and supporting the second device on its upper surface, wherein the lower end of the support member is joined to the lower support member, thereby forming a device case that houses the second device inside.

[0010] In the vehicle rear structure according to the third aspect of this disclosure, the first equipment can be supported on the upper surface of the equipment case that houses the second equipment inside, so a new base for supporting the first equipment is unnecessary. This makes it possible to suppress the occurrence of the submarine phenomenon while suppressing an increase in the number of parts.

[0011] The vehicle rear structure according to the fourth aspect of the present disclosure, in the configuration of the third aspect described above, wherein the support member is made of casting and is disposed between the first device and the second device.

[0012] In the vehicle rear structure according to the fourth aspect of this disclosure, a cast support member is provided between the first and second equipment, so that the heat radiated from the first and second equipment can be released by the support member.

[0013] The vehicle rear structure according to the fifth aspect of this disclosure is configured in the fourth aspect, wherein the lower support member is formed in a box shape with the upper side of the vehicle open.

[0014] In the vehicle rear structure according to the fifth aspect of this disclosure, the lower support member is formed in a box shape, so the second device is housed inside a box formed by the support member and the lower support member, and the heat trapped inside the box can be efficiently dissipated by the cast support member.

[0015] The rear vehicle structure according to the sixth aspect of this disclosure is such that, in any configuration of the first to fifth aspects described above, the support member is made of aluminum.

[0016] In the rear vehicle structure according to the sixth aspect of this disclosure, since the support member is made of aluminum, the heat radiated from the first equipment can be released by the support member, and the occurrence of the submarine phenomenon can be suppressed.

[0017] The rear vehicle structure according to the seventh aspect of this disclosure is, in any configuration relating to the third aspect described above, wherein the lower support member is made of aluminum.

[0018] In the vehicle rear structure according to the seventh aspect of this disclosure, since the lower support member is made of aluminum, the heat radiated from the second equipment can be released by the lower support member.

[0019] A vehicle rear structure according to one embodiment of this disclosure has the excellent effect of being able to suppress the occurrence of the submarine phenomenon.

[0020] This is a schematic exploded perspective view showing the main parts of a vehicle to which a vehicle rear structure according to one embodiment of this disclosure is applied. This is a side cross-section showing an example of a vehicle rear structure according to one embodiment of this disclosure.

[0021] The vehicle understructure according to the embodiments of this disclosure will be described below with reference to the drawings. Components indicated by the same reference numerals in each drawing are considered to be the same component. However, unless otherwise specified in the specification, each component is not limited to one, and there may be multiple such components.

[0022] Furthermore, explanations of redundant components and reference numerals in each drawing may be omitted. This disclosure is not limited to the following embodiments, and modifications can be made as appropriate within the scope of the purpose of this disclosure, such as omitting components, substituting them with different components, or combining one embodiment with various modifications.

[0023] (Vehicle Structure) Figure 1 is a schematic perspective view showing the main parts of a vehicle 10 to which the vehicle rear structure according to the present disclosure is applied, and Figure 2 is a side cross-section showing an example of the vehicle rear structure. The arrows FR, UP, and RH in the figures indicate the forward direction of the vehicle 10, the upward direction of the vehicle, and the right direction of the vehicle, respectively.

[0024] As shown in Figure 1, a battery pack 12, which serves as an energy storage device, is provided in the center of the vehicle 10 in the front-rear direction. The battery pack 12 is located at the bottom of the vehicle. Also, as an example, since the upper surface of the battery pack 12 constitutes the floor of the passenger compartment, the vehicle 10 in this embodiment does not have a floor panel.

[0025] On both sides of the battery pack 12 in the vehicle width direction, a pair of left and right rockers 15 are provided, extending in the vehicle's longitudinal direction. The rockers 15 are skeletal members formed in a substantially rectangular closed cross-section. The battery pack 12 is attached to the rockers 15 using fasteners (not shown).

[0026] The front end of the rocker 15 is connected to the front module 20. On the other hand, the rear end of the rocker 15 is connected to the rear module 30. The front module 20 and the rear module 30 are each integrally formed, for example, by casting.

[0027] The front module 20 is composed of, for example, a dash panel section 21, a suspension tower section 23, and a front side member section 25.

[0028] The dash panel section 21 extends in the vehicle width direction and the vehicle height direction, separating the interior space from the exterior space. The front side member sections 25 extend from both ends of the dash panel section 21 in the vehicle width direction toward the front of the vehicle, forming the road path in the event of a frontal collision. A pair of suspension tower sections 23 are provided on the left and right sides, each configured to support a suspension (not shown).

[0029] A first cross member 22 and a second cross member 24, which are cross members, are provided in the central part of the rocker 15 in the longitudinal direction of the vehicle. The first cross member 22 and the second cross member 24 extend in the vehicle width direction above the battery pack 12 and are installed between a pair of left and right rockers 15. Vehicle seats for the front seats (not shown) are attached to the first cross member 22 and the second cross member 24.

[0030] On the other hand, a third cross member 26, which is a cross member, is provided on the rear portion of the rocker 15 in the vehicle's longitudinal direction. The third cross member 26 also extends in the vehicle width direction above the battery pack 12 and is installed between the left and right pair of rockers 15.

[0031] As shown in Figure 2, the third cross member 26 is formed by overlapping two metal plates. Specifically, the third cross member 26 is formed by comprising a cross member body 26A and a stiffener 26B, with the outer stiffener 26B covering the inner cross member body 26A.

[0032] More specifically, the cross member body 26A is positioned inside the stiffener 26B and joined to the stiffener 26B, and the stiffener 26B is formed in a hat-shaped cross section with the lower side open in the side cross-sectional view shown in Figure 2. The lower ends of the cross member body 26A and the stiffener 26B are bent in the longitudinal direction of the vehicle and overlapped with each other.

[0033] (Battery Pack) As shown in Figure 2, a battery pack 12 is provided at the bottom of the vehicle 10 to store the power supplied to the motor of the vehicle 10. This battery pack 12 is composed of a box-shaped battery case 14 and a plurality of battery cells 16 housed inside the battery case 14. The battery case 14 is composed of an upper case 14A which constitutes the upper part of the battery case 14 and a lower case 14B which constitutes the lower part of the battery case 14.

[0034] The upper case 14A and the lower case 14B are formed in a plate shape with the vertical direction as the thickness direction and extending in the front-to-back and left-to-right directions. Multiple battery cells 16 are arranged in a front-to-back direction between the upper case 14A and the lower case 14B.

[0035] The upper case 14A is positioned above the battery cell 16 and is an upper cover that covers the battery cell 16. As described above, its upper surface constitutes the vehicle interior floor. An opening (not shown) is formed at the rear end of the upper case 14A in the vehicle's longitudinal direction. This opening communicates with the opening 42D of the equipment base 42, which will be described later, and through this opening, the internal space of the battery pack 12 and the internal space of the equipment case 40, which will be described later, are connected.

[0036] The battery pack 12 may consist only of an upper cover that covers the top of the battery cell 16. In this case, instead of the lower case 14B, a member that supports the battery cell 16 from below may be provided.

[0037] (Equipment Case) An equipment case 40, which houses various equipment, is located on the cabin R side above the battery case 14. The equipment case 40 includes an equipment base 42 as a lower support member and a lid 44 as a support member. The equipment base 42 is a box-shaped housing with the upper end, i.e., the upper end, open.

[0038] The device base 42 is positioned on the upper surface of the upper case 14A of the battery case 14 and comprises a lower wall portion 42A extending along the upper case 14A, a rear wall portion 42B extending upward from the rear end of the lower wall portion 42A, and a front wall portion 42C extending upward from the front end of the lower wall portion 42A. An opening 42D is formed in the rear portion of the lower wall portion 42A through which a harness or the like (not shown) passes. The device base 42 also comprises a front flange portion 42E extending forward from the upper end of the front wall portion 42C, and a boss portion 42F protruding downward from the front portion of the front flange portion 42E.

[0039] The front end of the equipment base 42 is then fixed to the third cross member 26 by screwing bolts (not shown), which are inserted from above into the front flange portion 42E and boss portion 42F of the equipment base 42, into nuts (not shown) provided on the third cross member 26.

[0040] In this embodiment, as an example, as shown in Figure 2, the equipment base 42 is formed such that the upper end of the rear wall portion 42B is located lower than that of the front wall portion 42C. Note that in Figure 1, the step difference between the rear wall portion 42B and the front wall portion 42C is not shown.

[0041] The material of the equipment base 42 is not particularly limited, but it is preferable that it be made of aluminum in order to improve the heat dissipation performance of heat-generating equipment such as relays and junction boxes 34, which will be described later. In other words, the material of the equipment base 42 is preferably a material with high thermal conductivity such as aluminum. Furthermore, it is even more preferable that it be a die-cast member (casting) formed by casting aluminum or the like. Note that the equipment base 42 does not necessarily have to be a casting, and may be formed from metal (for example, aluminum or stainless steel) plate material or resin. Even if the equipment base 42 is formed from metal plate material or resin, heat will be dissipated from heat-generating equipment such as relays and junction boxes 34 to the equipment base 42.

[0042] The cover 44 is positioned in a location that overlaps with the seat 46 (described later) when viewed from above, and is located below the seat 46 in the vehicle's vertical direction and above the battery pack 12 in the vehicle's vertical direction. Specifically, the cover 44 is a sealing member that closes the opening (open portion) at the upper end of the equipment base 42, and is fixed to the equipment base 42 using fastening members (not shown). The cover 44 comprises an upper wall portion 44A extending in the front-rear and left-right directions, a rear wall portion 44B extending downward from the rear end of the upper wall portion 44A, and a rear flange portion 44C extending rearward from the lower end of the rear wall portion 44B. The cover 44 also has an upper projection portion 44D that protrudes upward from the middle of the upper wall portion 44A in the front-rear direction.

[0043] The cover body 44 has thermal conductivity, is preferably formed of a material with high thermal conductivity, and is made of aluminum as an example. Note that the cover body 44 may also be formed of a metal plate material (e.g., aluminum or stainless steel), a resin having rigidity comparable to that of metal, or the like. Even when the device pedestal 42 is formed of a metal plate material, resin, or the like, heat is dissipated from a heat-generating device such as a relay to the device pedestal 42. Further, the cover body 44 is formed of a die-cast member (casting) formed by casting aluminum or the like.

[0044] Since the cover body 44 is attached to the device pedestal 42 from the upper side, a second device arrangement space 32 is formed between the cover body 44 and the device pedestal 42. In this second device arrangement space 32, a junction box 34 serving as a second device is arranged. That is, the lower end of the cover body 44 is joined to the device pedestal 42, thereby forming a device case 40 that accommodates the junction box 34 therein. Note that the junction box 34 is supported on the upper surface of the lower wall portion 42A of the device pedestal 42, and is fixed to the lower wall portion 42A of the device pedestal 42 via a fixing member not shown in the drawings.

[0045] Although not shown in the drawings, a relay, auxiliary equipment, and the like are provided inside the junction box 34. The auxiliary equipment includes, for example, a PDU (Power Distribution Unit), an ECU (Electronic Control Unit), and the like. The relay and the auxiliary equipment are connected to the battery pack 12 via a wire harness or the like (not shown), and are electrically connected to the battery pack 12. Heat-generating devices such as a relay are driven by electric power supplied from the battery pack 12, and may generate heat along with driving.

[0046] The device case 40 accommodating the junction box 34 is partially arranged above an upper case 14A of the battery pack 12. The expression "partially arranged" means, as an example, that in the battery pack 12 extending in the vehicle front-rear direction and the vehicle width direction, the device case 40 is arranged at a part (e.g., the rear side) in the vehicle front-rear direction.

[0047] (Auxiliary Machine Cover) The auxiliary machine cover 50 is formed to be thinner than the above-described device pedestal 42 and the lid body 44 by performing pressing processing or the like on a steel plate material. Here, the auxiliary machine cover 50 of the present embodiment has a divided structure in the vehicle width direction (a three-part divided structure as one example). The bending rigidity of the auxiliary machine cover 50 in the vehicle vertical direction is set to be lower than the bending rigidity of the above-described device pedestal 42 and lid body 44 in the vehicle vertical direction. The auxiliary machine cover 50 also includes an upper wall portion 50A arranged to face the upper wall portion 44A of the lid body 44 in the vertical direction, and a front wall portion 50B extending downward from the front end of the upper wall portion 50A.

[0048] When the auxiliary machine cover 50 is attached to the lid body 44 from the upper side, a first device arrangement space 36 is formed between the auxiliary machine cover 50 and the lid body 44. In the first device arrangement space 36, on the front side of the upper protruding portion 44D, a charging device 38 such as a 2IN1 device as the first device is arranged. In the present embodiment, the charging device 38 is supported on the upper surface of the upper wall portion 44A of the lid body 44 on the front side in the vehicle front-rear direction, specifically, on the upper surface of the upper wall portion 44A on the front side of the upper protruding portion 44D, and is fixed to the upper surface of the upper wall portion 44A of the lid body 44 via a fixing member not shown. Further, as shown in FIG. 1 and FIG. 2, the lid body 44 is disposed between the junction box 34 and the charging device 38.

[0049] (Seat, Etc.) On the upper side of the auxiliary machine cover 50, a seat 46 that constitutes a part of the rear seat of the vehicle is provided. The seat 46 is arranged on the upper side in the vehicle vertical direction of the vehicle rear portion of the battery pack 12. A carpet 48 is provided on the lower side of the seat 46, and the carpet 48 covers the device case 40 and the third cross member 26 from the front side.

[0050] Further, the vertical gap between the lid body 44 and the seat 46 at the front end portion of the charging device 38 is set to be wider than the vertical gap between the lid body 44 and the seat 46 at the rear end portion of the charging device 38. Furthermore, the vertical gap between the lid body 44 and the seat 46 increases from the rear end portion of the charging device 38 toward the front end portion of the charging device 38.

[0051] (Operation and Effects) Next, the operation and effects of this embodiment will be described.

[0052] In the vehicle rear structure according to this embodiment, a cover 44 is provided as a support member at a position that overlaps with the seat 46 when viewed from above, on the lower side of the seat 46 in the vehicle's vertical direction and on the upper side of the battery pack 12 in the vehicle's vertical direction. Therefore, the cover 44 can prevent the seat 46 from sinking during a frontal collision. This suppresses the sinking of the hip point and increases the restraining force of the seat belt on the occupant during a frontal collision, thereby suppressing the occurrence of the submarine effect.

[0053] Furthermore, in the vehicle rear structure of this embodiment, the charging equipment 38 is supported on the upper surface of the upper wall portion 44A of the front cover 44 in the front-rear direction of the vehicle. Therefore, the charging equipment 38 as the first device, specifically the auxiliary cover 50 that covers the charging equipment 38, can lift the front end of the seat 46. This suppresses the forward movement of occupants seated in the seat 46 during a frontal collision, thereby further suppressing the occurrence of the submarine phenomenon.

[0054] Furthermore, in the vehicle rear structure of this embodiment, the charging equipment 38, which is the first equipment, is supported on the upper surface of the equipment case 40 that houses the junction box 34, which is the second equipment, so a new base to support the charging equipment 38 is unnecessary. This makes it possible to suppress the occurrence of the submarine phenomenon while suppressing an increase in the number of parts.

[0055] Furthermore, in the vehicle rear structure of this embodiment, a cast iron cover 44 is provided between the charging equipment 38, which is the first piece of equipment, and the junction box 34, which is the second piece of equipment. This allows the heat generated from the charging equipment 38 and the junction box 34 to escape.

[0056] Furthermore, in the vehicle rear structure of this embodiment, since the equipment base 42 is formed in a box shape, the junction box 34 is housed inside a box composed of a lid 44 and an equipment base 42, and the heat trapped inside the box can be efficiently dissipated by the cast lid 44 and equipment base 42.

[0057] Furthermore, in the vehicle rear structure of this embodiment, since the cover 44 is made of aluminum, the cover 44 can dissipate the heat dissipated from the charging equipment 38 and the junction box 34, and suppress the occurrence of the submarine phenomenon.

[0058] Furthermore, in the vehicle rear structure of this embodiment, since the equipment base 42 is made of aluminum, the heat dissipated from the junction box 34 can be released by the equipment base 42.

[0059] Furthermore, in the vehicle rear structure of this embodiment, the charging equipment 38 is fixed to the upper wall portion 44A, which is the front part of the cover 44, and is positioned above the upper wall portion 44A. This allows the charging equipment 38 to be easily maintained from the cabin R side.

[0060] Furthermore, some of the components of this embodiment described above can be omitted or modified.

[0061] 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.

[0062] Furthermore, the disclosure of Japanese Patent Application No. 2025-052179, 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 one or more battery cells housed inside; a seat positioned above the rear of the vehicle where the energy storage device is located; and a support member positioned in a location overlapping the seat in a top view, below the seat in the vehicle's vertical direction and above the energy storage device in the vehicle's vertical direction, with its upper surface supporting a first device.

2. The vehicle rear structure according to claim 1, wherein the support member supports the first device on the upper surface on the front side in the longitudinal direction of the vehicle.

3. The vehicle rear structure according to claim 1, further comprising a lower support member disposed on the upper surface of the energy storage device and supporting a second device on its upper surface, wherein the lower end of the support member is joined to the lower support member, thereby forming a device case that houses the second device inside.

4. The vehicle rear structure according to claim 3, wherein the support member is made of casting and is disposed between the first device and the second device.

5. The vehicle rear structure according to claim 4, wherein the lower support member is formed in a box shape with the upper side of the vehicle open.

6. The vehicle rear structure according to claim 1, wherein the support member is made of aluminum.

7. The vehicle rear structure according to claim 3, wherein the lower support member is made of aluminum.

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