Vehicle rear structure

Abstract

To provide a vehicle rear part structure having a component which protects an on-vehicle battery stack and can be used as an air channel.SOLUTION: A vehicle rear part structure 20 comprises side frames 21, and a rear collision countermeasure member 28. The side frames 21 extend along a cross direction, and are arranged at positions sandwiching a battery pack 10 in a width direction. The rear collision countermeasure member 28 is constructed between the side frames 21, and is located on a rear side of the battery pack 10. Further, the rear collision countermeasure member 28 is so configured that air blowing to a battery stack 23 included in the battery pack 10 circulates therein.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The present invention relates to a vehicle rear structure. [Background technology]

[0002] Electric vehicles and hybrid vehicles are equipped with a large-capacity vehicle battery that supplies power to the motor that drives the vehicle. To ensure sufficient continuous driving distance, this vehicle battery is heavy and occupies a large volume. Therefore, the vehicle battery is often located, for example, under the seat or under the rear floor.

[0003] Patent Document 1 describes a battery module that can protect a battery from impacts such as those caused by a vehicle collision. The battery module described in this document includes a lower frame for fixing the battery module, which includes a front frame, a rear frame, and side frames. The front frame and the side frames also have fastening flanges that can be partially overlapped and fastened together to the vehicle side. This configuration can enhance the protective effect of the battery module.

[0004] Furthermore, Patent Document 2 describes an air conditioning structure that uses a cross member as an air passage. Specifically, a hot air passage and a cold air passage for air conditioning are formed in the cross member that is placed between the roof side rails of the roof frame that constitutes the body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-89448 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-183959 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the inventions described in the above-mentioned patent documents leave room for improvement in terms of effectively protecting the battery from impact during a collision.

[0007] Specifically, in the invention described in Patent Document 1, the battery is protected by a frame attached to the vehicle, but the use of multiple frames results in a bulky protective structure, which can lead to an increase in vehicle weight, a complex vehicle structure, and high costs.

[0008] Furthermore, the invention described in Patent Document 2 describes using a cross member as an air passage, thereby allowing a vehicle component to also serve as an air passage, but does not consider the issue of protecting the battery with the cross member.

[0009] The present invention has been made in consideration of these problems, and an object of the present invention is to provide a vehicle rear structure that has a component that can protect an on-board battery stack and can also be used as an air passage. [Means for solving the problem]

[0010] The present invention provides a vehicle rear structure that reduces impacts acting on a battery pack during a collision, the vehicle rear structure comprising side frames and a rear-impact countermeasure member, the side frames extending in the front-rear direction and disposed in positions sandwiching the battery pack in the width direction, the rear-impact countermeasure member bridged between the side frames and disposed on the rear side of the battery pack, and further, the rear-impact countermeasure member is configured to allow air blown to a battery stack included in the battery pack to circulate, The rear impact prevention member has an inclined surface that slopes upward toward the front, and the inclined surface overlaps with an upper end of the battery pack when viewed from the front of the vehicle. It is characterized by: [Effects of the Invention]

[0011] According to the vehicle rear structure of the embodiment of the present invention, the rear impact countermeasure member, which is a member that absorbs impacts acting on the battery pack, also serves as a member through which air for conditioning the battery stack flows, thereby making it possible to partially eliminate the need for air conditioning ducts, thereby reducing the number of parts around the battery pack, simplifying the configuration, and reducing costs. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view showing a vehicle equipped with a vehicle rear structure according to an embodiment of the present invention; [Figure 2] 1 is a side cross-sectional view showing a vehicle equipped with a vehicle rear structure according to an embodiment of the present invention. [Figure 3A] 1 is a perspective view showing a vehicle rear structure according to an embodiment of the present invention; [Figure 3B] 1 is a rear view showing a vehicle rear structure according to an embodiment of the present invention; [Figure 4] 1 is a cutaway perspective view showing a vehicle rear structure according to an embodiment of the present invention; [Figure 5A] 1 is a side cross-sectional view showing a vehicle rear structure according to an embodiment of the present invention. [Figure 5B] 1 is an enlarged side cross-sectional view showing a vehicle rear structure according to an embodiment of the present invention. [Figure 6A] 2 is a perspective view showing a configuration of a communication duct and the like in the vehicle rear structure according to the embodiment of the present invention. FIG. [Figure 6B] 2 is a top view showing the configuration of a communication duct and the like in the vehicle rear structure according to the embodiment of the present invention. FIG. [Figure 7A] 3A to 3C are side cross-sectional views sequentially showing how the vehicle rear structure according to the embodiment of the present invention is deformed. [Figure 7B] 3A to 3C are side cross-sectional views sequentially showing how the vehicle rear structure according to the embodiment of the present invention is deformed. [Figure 8A] 3A to 3C are side cross-sectional views sequentially showing how the vehicle rear structure according to the embodiment of the present invention is deformed. [Figure 8B]3A to 3C are side cross-sectional views sequentially showing how the vehicle rear structure according to the embodiment of the present invention is deformed. DETAILED DESCRIPTION OF THE INVENTION

[0013] A vehicle 11 equipped with a vehicle rear structure 20 according to an embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, the front, rear, up, down, left and right directions are used, and left and right refer to the left and right when the vehicle 11 is viewed from the rear. Furthermore, in the following description, the same components are generally designated by the same reference numerals, and repeated description will be omitted.

[0014] FIG. 1 is a perspective view showing a vehicle 11 equipped with a vehicle rear structure 20.

[0015] The vehicle 11 is, for example, an automobile, a train, or the like, and is equipped with a battery pack 10 for supplying power to a motor and electrical components mounted on a vehicle body 12. The vehicle 11 is, for example, an EV (Electrical Vehicle), an HEV (Hybrid Electrical Vehicle), or a PHEV (Plug-in Hybrid Electrical Vehicle). The vehicle 11 is equipped with a battery pack 10 having a high power storage function.

[0016] The battery pack 10 is disposed in a storage space 13 formed below a rear floor 15 .

[0017] The vehicle rear structure 20 is provided to absorb the impact acting on the battery pack 10 in the event of a collision, and is disposed in a position surrounding the battery pack 10. The structure of the vehicle rear structure 20 will be described later with reference to FIG. 3 etc.

[0018] FIG. 2 is a side cross-sectional view showing a vehicle 11 equipped with a vehicle rear structure 20.

[0019] The body 12 of the vehicle 11 has a frame 18. The frame 18 extends continuously from the front to the rear near the bottom of the body 12. The frames 18 are disposed on both the right and left ends of the body 12. Side frames 21 are disposed near the rear ends of the frame 18. A rear frame 16 extending in the width direction is disposed near the rear ends of the side frames 21. As will be described later, the upper end of the battery pack 10 is disposed above the upper ends of the side frames 21.

[0020] The vehicle rear structure 20 includes a side frame 21 and a rear collision countermeasure member 28.

[0021] The rear-end collision countermeasure member 28 is disposed immediately rearward of the battery pack 10. The rear-end collision countermeasure member 28 has the function of mitigating impact caused by a rear-end collision accident. Details of the rear-end collision countermeasure member 28 will be described later with reference to Figures 5A and 5B, etc.

[0022] Here, a rear-end collision will be described. A rear-end collision is an accident in which a following vehicle, such as a large vehicle 29, collides with the vehicle 11 from behind. If the lower end of the body of the large vehicle 29 is positioned higher than the upper surface of the side frame 21, a so-called override rear-end collision may occur. If an override rear-end collision occurs, there is a risk that a large impact will act on the battery pack 10 of the vehicle 11. In this embodiment, as will be described later, a rear-end collision prevention member 28 is provided on the vehicle 11 to protect the battery pack 10 from an override rear-end collision.

[0023] Fig. 3A is a perspective view showing the vehicle rear structure 20. Fig. 3B is a rear view showing the vehicle rear structure 20.

[0024] 3A, the rear-end collision countermeasure member 28 is disposed near the rear side of the battery pack 10. The rear-end collision countermeasure member 28 is a generally hollow member extending in the left-right direction, and is made of, for example, extruded aluminum material. As will be described later, the rear-end collision countermeasure member 28 is configured to allow air to circulate through the battery stack 23 included in the battery pack 10.

[0025] The battery pack 10 is a module that incorporates a battery stack 23, which will be described later, and its configuration will be described later with reference to FIG. 5A and the like.

[0026] A blower 31 and an introduction duct 32 are connected to the left end of the rear-end collision prevention member 28.

[0027] The blower 31 has a built-in motor and fan for blowing air. The left end of the introduction duct 32 is connected to the blower 31.

[0028] The left end of the introduction duct 32 is connected to the blower 31, and the right end is connected to the rear-end collision prevention member 28. The right end of the rear-end collision prevention member 28 may be closed to improve airtightness.

[0029] Air from the passenger compartment 14 of the vehicle 11 passes through the blower 31, the inlet duct 32, and the rear-end collision prevention member 28, and is then blown to the battery stack 23 built into the battery pack 10. This cools the battery stack 23 to a predetermined temperature range. The air path along which the air travels from the rear-end collision prevention member 28 to the battery pack 10 will be described later with reference to FIG. 6A etc.

[0030] 3B, side frames 21 are disposed at the left and right ends of the vehicle body 12. A rear-end collision countermeasure member 28 is installed between the side frames 21 of the battery pack 10 and is disposed on the rear side of the battery pack 10. The rear-end collision countermeasure member 28 is also disposed above the side frames 21. Both left and right ends of the rear-end collision countermeasure member 28 are joined to the upper surfaces of the side frames 21 by welding or fastening.

[0031] The upper surface of the battery pack 10 is disposed above the upper surfaces of the side frames 21. Specifically, the length L10 by which the upper surface of the battery pack 10 protrudes upward from the upper surfaces of the side frames 21 is, for example, approximately 6 cm. With this configuration, there is a concern that a large impact may be applied to the vehicle rear structure 20 in the event of the aforementioned override rear collision. In this embodiment, a rear collision countermeasure member 28 is disposed behind the battery pack 10, and the rear collision countermeasure member 28 is disposed above the side frames 21. Therefore, the battery pack 10 can be protected from rear collisions, as will be described later.

[0032] FIG. 4 is a cutaway perspective view showing the vehicle rear structure 20. As shown in FIG.

[0033] In the vehicle rear structure 20 , the battery pack 10 is disposed in an area surrounded by a rear floor 15 and a vehicle body floor 17 .

[0034] The battery pack 10 includes, for example, a plurality of battery stacks 23 built therein.

[0035] The battery stack 23 is configured by connecting multiple battery cells. The battery cells are, for example, secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries. The battery cells have, for example, a rectangular flat plate shape and are arranged at approximately equal intervals with gaps between them along the longitudinal direction of the battery stack 23, i.e., the left-right direction.

[0036] The battery pack 10 has a battery case 33 and a battery cover 34. The battery case 33 is a generally container-shaped member with an open top. The battery cover 34 is a generally plate-shaped member that closes the top opening of the battery case 33 from above. The battery stack 23 and other components are housed in a space that is generally sealed by the battery case 33 and the battery cover 34.

[0037] Fig. 5A is a side cross-sectional view showing the vehicle rear structure 20. Fig. 5B is an enlarged side cross-sectional view showing the vehicle rear structure 20.

[0038] 5A, a rear-end collision countermeasure member 28 is disposed on the rear side of the battery pack 10. The upper end of the rear-end collision countermeasure member 28 is disposed higher than the upper end of the battery pack 10. Furthermore, the upper end of the rear-end collision countermeasure member 28 is disposed higher than the upper end of the battery stack 23. With this configuration, as will be described later, when the above-described override rear-end collision occurs, it is possible to protect the battery pack 10 and the battery stack 23 from the rear-end collision.

[0039] The rear-end collision prevention member 28 has an inclined surface 24. The upper end of the inclined surface 24 is positioned at the same height as the rear end of the upper surface of the battery cover 34 of the battery pack 10 or higher than the rear end of the upper surface of the battery cover 34. With this configuration, in the event of an override rear-end collision, the rear-end collision prevention member 28 deflects the large vehicle 29 shown in FIG. 2 upward, thereby significantly protecting the battery stack 23 from the override rear-end collision. Furthermore, as described above, the rear-end collision prevention member 28 is made of extruded aluminum material rather than a bent steel plate. Therefore, the high mechanical strength of the rear-end collision prevention member 28 itself also significantly enhances the effect of protecting the battery pack 10 by the rear-end collision prevention member 28. Furthermore, the rear-end collision prevention member 28 is positioned higher than the upper surface of the side frame 21. With this configuration, the impact caused by a rear-end collision is deflected upward, significantly enhancing the effect of protecting the battery stack 23 from the override rear-end collision.

[0040] 5B, rear-end collision prevention member 28 has inclined surface 24 that slopes upward toward the front. Inclined surface 24 is a surface formed on the rear upper end of rear-end collision prevention member 28. With this configuration, in the event of an override rear-end collision, large vehicle 29 shown in FIG. 2 can escape along the upper surface of battery cover 34, thereby significantly protecting battery stack 23 from the override rear-end collision.

[0041] The angle θ of the inclined surface 24 from the horizontal plane is preferably 45 degrees or less, and particularly preferably 30 degrees or less. By setting the angle θ within this range, the effect of the rear-end collision prevention member 28 in protecting the battery stack 23 can be made significant.

[0042] Fig. 6A is a perspective view showing the configuration of the communication duct 25 in the vehicle rear structure 20. Fig. 6B is a top view showing the configuration of the communication duct 25 in the vehicle rear structure 20 from a different angle.

[0043] 6A and 6B, a communication duct 25 is connected to an intermediate portion of rear-end collision prevention member 28. Communication duct 25 connects rear-end collision prevention member 28 to battery stack 23 shown in FIG.

[0044] The communication duct 25 has a first communication duct 26 and a second communication duct 27. The rear end of the first communication duct 26 communicates with the left end portion of the rear-end collision prevention member 28. The front end of the first communication duct 26 communicates with the front battery stack 23 shown in FIG. 4. The rear end of the second communication duct 27 communicates with the right end portion of the rear-end collision prevention member 28. The front end of the second communication duct 27 communicates with the rear battery stack 23 shown in FIG. 4.

[0045] First air passage 35 is an air passage formed inside introduction duct 32, rear-end collision prevention member 28, and first communication duct 26. Second air passage 36 is an air passage formed inside introduction duct 32, rear-end collision prevention member 28, and second communication duct 27.

[0046] The second air passage 36 is formed to be longer than the first air passage 35. In this embodiment, the cross-sectional area of ​​the second communication duct 27 is made larger than the cross-sectional area of ​​the first communication duct 26. This reduces the pressure loss in the second communication duct 27, which has a long air passage length, and makes it possible to equalize the pressure loss between the first communication duct 26 and the second communication duct 27. This reduces the temperature difference between the front battery stack 23 (see FIG. 4) cooled by the air passing through the first air passage 35 and the rear battery stack 23 (see FIG. 4) cooled by the air passing through the second air passage 36.

[0047] Furthermore, the interior of the rear-end impact countermeasure member 28 has a straight shape from the left end to the right end, with no localized reduction in cross-sectional area, which reduces pressure loss inside the rear-end impact countermeasure member 28 and prevents stress from concentrating on specific portions of the rear-end impact countermeasure member 28.

[0048] 7A, 7B, 8A and 8B are side cross-sectional views sequentially showing a situation in which a large vehicle 29 overrides and crashes into a vehicle 11 from behind.

[0049] Referring to FIG. 7A, when a large vehicle 29 overrides and crashes into the vehicle 11 from behind, the body of the large vehicle 29 enters the interior of the vehicle 11 from above the rear frame 16.

[0050] 7B, when the body of large vehicle 29 moves forward, the lower front end of large vehicle 29 comes into contact with inclined surface 24 of rear-end collision countermeasure member 28. When this happens, the impact of the collision is transmitted from rear-end collision countermeasure member 28 to side frame 21, and as a result, the impact is mitigated.

[0051] 8A, large vehicle 29 further enters vehicle 11 from the rear. At this time, the front lower end of large vehicle 29 is guided upward by inclined surface 24 of rear-end collision prevention member 28. As a result, the entire lower end portion of vehicle 11 sinks downward. This causes the rear portion of battery pack 10 to also sink downward, preventing the impact from being directly input to battery pack 10.

[0052] 8B, the front end of large vehicle 29 is stopped above battery pack 10. Due to the action of rear-end collision prevention member 28 described above, large vehicle 29 does not apply a large impact to battery pack 10. Therefore, damage to battery stack 23 built into battery pack 10 is suppressed.

[0053] The above-described embodiment can provide the following main effects.

[0054] 3A, rear-end collision countermeasure member 28, which is a member that absorbs impacts acting on battery pack 10, also serves as a member through which air for conditioning battery stack 23 flows, thereby making it possible to partially eliminate ducts for air conditioning. This reduces the number of parts around battery pack 10, resulting in a simplified configuration and reduced costs.

[0055] Referring to Figures 7A to 8B, when a rear-end collision occurs, the rear-end collision object that hits vehicle 11 from behind runs onto inclined surface 24, thereby mitigating the impact caused by the rear-end collision and protecting battery pack 10 from the impact.

[0056] 3B, both end portions of rear-end collision countermeasure member 28 are joined to side frames 21, so that the impact input to rear-end collision countermeasure member 28 due to a rear-end collision can be dissipated to side frames 21.

[0057] Referring to Figure 5A, the upper end of rear-end collision prevention member 28 is positioned higher than the upper end of battery stack 23, so that in the event of a rear-end collision, the rear-end collision object will ride up onto rear-end collision prevention member 28, thereby mitigating the impact acting on battery stack 23.

[0058] Referring to FIG. 6A, by reducing the pressure loss in second communication duct 27 having a long air passage length, air can be supplied to a plurality of battery stacks 23 evenly.

[0059] Although the embodiments of the present invention have been described above, the present invention is not limited to these and can be modified within the scope of the present invention. In addition, the above-described embodiments can be combined with each other. [Explanation of symbols]

[0060] 10 Battery pack 11 vehicles 12 Body 13 Storage Space 14 Cabin 15 Rear floor 16 Rear frame 17 Body floor 18 frames 20 Vehicle rear structure 21 Side frame 23 Battery Stack 24 Slope 25 Connecting duct 26 First connecting duct 27 Second connecting duct 28 Rear impact protection components 29 Large vehicles 31 Blower 32 Inlet duct 33 Battery case 34 Battery cover 35 1st wind path 36 2nd wind path

Claims

1. A vehicle rear structure that reduces the impact on the battery pack during a collision, The vehicle is provided with a side frame and a rear-end collision prevention member, the side frames extend along a front-rear direction and are disposed at positions that sandwich the battery pack in a width direction; the rear-end collision prevention member is installed between the side frames and is disposed rearward of the battery pack, Furthermore, the rear-end collision prevention member is configured to allow air to flow to a battery stack included in the battery pack, The rear impact prevention member has an inclined surface that slopes upward toward the front, and the inclined surface overlaps with the upper end of the battery pack when viewed from the front of the vehicle.

2. 2. The vehicle rear structure according to claim 1, wherein both end portions of the rear impact prevention member are joined to the side frames.

3. 3. The vehicle rear structure according to claim 1, wherein an upper end of the rear impact prevention member is disposed above an upper end of the battery stack.

4. A vehicle rear structure as described in claim 1, characterized in that the rear impact prevention member is made of extruded aluminum material.

5. A vehicle rear structure that reduces impact on a battery pack during a collision, The vehicle is provided with a side frame and a rear-end collision prevention member, the side frames extend along a front-rear direction and are disposed at positions that sandwich the battery pack in a width direction; the rear-end collision prevention member is installed between the side frames and is disposed rearward of the battery pack, Furthermore, the rear-end collision prevention member is configured to allow air to flow to a battery stack included in the battery pack, a communication duct that connects the rear-end collision prevention member and the battery stack, the communication duct has a first communication duct and a second communication duct that forms an air passage longer than the first communication duct, A vehicle rear structure, wherein the cross-sectional area of ​​the second communication duct is larger than the cross-sectional area of ​​the first communication duct.

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