Battery pack protection structure

Abstract

To provide a battery pack protection structure that can protect the battery pack from the impact force during a rear-end collision of a vehicle. [Solution] The upper case side flange portion 12A at the lower end of the rear surface of the upper case 12 has an extended portion 12B that extends rearward from the lower case side flange portion 13A at the upper end of the rear surface of the lower case 13. The rear bracket 39 has an upper bracket 39A fixed to the upper cross frame 33, a lower bracket 39B fixed to the lower cross frame 34, and a joint portion 39C to which the upper bracket 39A and the lower bracket 39B are joined together in an overlapping state that extends in the longitudinal direction of the vehicle. The joint portion 39C is positioned at the same location as the extended portion 12B in the vertical direction of the vehicle and faces the extended portion 12B in the longitudinal direction of the vehicle.

Description

Technical Field

[0001] The present invention relates to a protection structure for a battery pack.

Background Art

[0002] Patent Document 1 describes a support structure for a power storage device (battery pack) mounted on a vehicle, which has a frame unit that surrounds the power storage device by a plurality of frames connected to each other. In this support structure, the frame unit has a guide portion that hits against the structural frame of the vehicle due to the displacement of the frame unit that has received an external force applied to the vehicle, and displaces the frame unit in a direction avoiding the structural frame. Further, the power storage device is disposed in a lower space of a luggage room behind the rear seat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology, at the time of a rear collision of the vehicle, luggage or the like placed in the luggage room collides with the frame unit from the rear, and there is a risk that a component of the frame unit displaced forward due to the collision may damage the battery pack.

[0005] The present invention has been made paying attention to the above problems, and an object thereof is to provide a protection structure for a battery pack that can protect the battery pack from an impact force at the time of a rear collision of the vehicle.

Means for Solving the Problems

[0006] The present invention relates to a battery pack protection structure in a vehicle comprising a battery pack located on the rear floor of the luggage compartment at the rear of the vehicle, and a frame unit that surrounds the battery pack with a plurality of frames connected to each other and is fixed to the rear floor, wherein the frame unit has a lower cross frame extending in the vehicle width direction behind and below the battery pack, an upper cross frame extending in the vehicle width direction behind and above the battery pack, and a bracket extending in the vehicle vertical direction behind the battery pack and connected to the lower cross frame and the upper cross frame, wherein the battery pack has a battery body and a battery case that covers the battery body, and the battery case has a lower case that covers the battery body from below and a bracket that covers the battery body from above The bracket comprises an upper case connected to a lower case, a lower case side flange portion extending to the rear of the vehicle and connected to the upper case formed at the upper end of the rear surface of the lower case, an upper case side flange portion extending to the rear of the vehicle and connected to the lower case side flange portion formed at the lower end of the rear surface of the upper case, the upper case side flange portion having an extension portion extending further rearward than the lower case side flange portion, the bracket comprises an upper bracket fixed to the upper cross frame, a lower bracket fixed to the lower cross frame, and a joint portion in which the upper bracket and the lower bracket overlap and are joined to each other in the longitudinal direction of the vehicle, the joint portion being positioned at the same location as the extension portion in the vertical direction of the vehicle and facing the extension portion in the longitudinal direction of the vehicle. [Effects of the Invention]

[0007] Thus, according to the present invention, it is possible to provide a battery pack protection structure that can protect the battery pack from the impact force during a rear-end collision of a vehicle. [Brief explanation of the drawing]

[0008] [Figure 1]Figure 1 is a rear perspective view of a vehicle equipped with a battery pack protection structure according to one embodiment of the present invention. [Figure 2] Figure 2 is a plan view of the rear of a vehicle equipped with a battery pack protection structure according to one embodiment of the present invention. [Figure 3] Figure 3 is a cross-sectional view of the battery pack shown in Figure 2, taken along the line III-III. [Figure 4] Figure 4 is a plan view of a battery pack and lower bracket equipped with a battery pack protection structure according to one embodiment of the present invention. [Figure 5] Figure 5 is a cross-sectional view of the battery pack and bracket shown in Figure 3, taken along the VV direction. [Figure 6] Figure 6 shows the state of the rear of a vehicle equipped with a battery pack protection structure according to one embodiment of the present invention during a rear-end collision. [Modes for carrying out the invention]

[0009] A battery pack protection structure according to one embodiment of the present invention is a battery pack protection structure in a vehicle comprising a battery pack located on the rear floor of the luggage compartment at the rear of the vehicle, and a frame unit that surrounds the battery pack with a plurality of frames connected to each other and is fixed to the rear floor, wherein the frame unit has a lower cross frame extending in the vehicle width direction behind and below the battery pack, an upper cross frame extending in the vehicle width direction behind and above the battery pack, and a bracket extending in the vehicle vertical direction behind the battery pack and connected to the lower cross frame and the upper cross frame, and the battery pack has a battery body and a battery case that covers the battery body, and the battery case has a lower case that covers the battery body from below, and a battery The battery pack protection structure comprises an upper case that covers the main body from above and is connected to the lower case, with a lower case side flange portion formed at the upper end of the rear surface of the lower case, extending to the rear of the vehicle and connected to the upper case, and an upper case side flange portion formed at the lower end of the rear surface of the upper case, extending to the rear of the vehicle and connected to the lower case side flange portion, the upper case side flange portion having an extended portion that extends further rearward than the lower case side flange portion, and the bracket comprises an upper bracket fixed to the upper cross frame, a lower bracket fixed to the lower cross frame, and a joint portion to which the upper bracket and lower bracket are joined to each other in a state where they overlap and extend in the longitudinal direction of the vehicle, the joint portion being positioned at the same position as the extended portion in the vertical direction of the vehicle and facing the extended portion in the longitudinal direction of the vehicle. Thus, the battery pack protection structure according to one embodiment of the present invention can protect the battery pack from impact forces during a rear collision of the vehicle. [Examples]

[0010] The following describes a battery pack protection structure according to one embodiment of the present invention, with reference to the drawings. Figures 1 to 6 show the battery pack protection structure according to one embodiment of the present invention. In Figures 1 to 6, the directions indicated by up, down, right, and left are the directions as viewed from the driver's seat.

[0011] In Figures 1 and 2, the vehicle 1 comprises a body 2. A rear floor 2A is provided at the rear of the body 2. The rear floor 2A forms the floor surface of the luggage compartment 2B located behind the rear seats (not shown).

[0012] A battery pack 10 is mounted on the rear floor 2A. The battery pack 10 consists of a battery pack with multiple cells electrically connected, and supplies power to a motor for driving (not shown).

[0013] The battery pack 10 is enclosed by a frame unit 30. The frame unit 30 encloses the battery pack 10 with multiple frames connected to each other. This frame unit 30 is fixed to the rear floor 2A.

[0014] The frame unit 30 includes a lower cross frame 32 that extends in the vehicle width direction in front of and below the battery pack 10, and an upper cross frame 31 that extends in the vehicle width direction in front of and above the battery pack 10. The lower cross frame 32 and the upper cross frame 31 are made of highly rigid steel pipes or the like, protecting the battery pack 10 from loads acting from the front. The frame unit 30 also has three front brackets 36 that extend in the vehicle vertical direction in front of the battery pack 10 and are connected to the lower cross frame 32 and the upper cross frame 31.

[0015] The front bracket 36 is connected to the left end, center, and right end in the vehicle width direction of the lower cross frame 32 and the upper cross frame 31, respectively, and connects the lower cross frame 32 and the upper cross frame 31.

[0016] The frame unit 30 has a lower cross frame 34 that extends in the vehicle width direction behind and below the battery pack 10, and an upper cross frame 33 that extends in the vehicle width direction behind and above the battery pack 10. The lower cross frame 34 and the upper cross frame 33 are composed of highly rigid steel pipes or the like, and protect the battery pack 10 from loads acting from the rear. Further, the frame unit 30 has three rear brackets 39 that extend in the vehicle vertical direction behind the battery pack 10 and are connected to the lower cross frame 34 and the upper cross frame 33.

[0017] The rear brackets 39 are respectively connected to the left end, the center, and the right end in the vehicle width direction of the lower cross frame 34 and the upper cross frame 33, and connect the lower cross frame 34 and the upper cross frame 33. The rear brackets 39 function as columns that support the upper cross frame 33 above the lower cross frame 34. Further, the rear brackets 39 have a function of protecting the battery pack 10 from loads acting from the rear between the lower cross frame 34 and the upper cross frame 33.

[0018] The battery pack 10 has connecting members 43, 44, 45. The connecting members 43, 44, 45 extend in the vehicle front-rear direction above the battery pack 10. The connecting members 43, 44, 45 are respectively connected to the left end, the center, and the right end in the vehicle width direction of the front upper cross frame 31 and the rear upper cross frame 33, and connect the upper cross frame 31 and the upper cross frame 33.

[0019] The frame unit 30 has a pair of fixed rails 41, 42. The fixed rails 41, 42 extend in the front-rear direction at the lower part of the lower cross frames 32, 34, and are fixed to the lower cross frames 32, 34 and the rear floor 2A. The fixed rail 41 is fixed to the left end of the lower cross frames 32, 34. The fixed rail 42 is fixed to the right end of the lower cross frames 32, 34.

[0020] A plurality of L-shaped brackets 46 are fixed to the lower portions of the front and rear surfaces of the battery pack 10. The L-shaped brackets 46 are fixed to the upper portions of the lower cross frames 32 and 34. The battery pack 10 is supported by the lower cross frames 32 and 34 via the L-shaped brackets 46 on its front side and rear side.

[0021] On the rear floor 2A of the luggage room 2B, a load is placed behind the frame unit 30. In this embodiment, a tool box 20 is placed on the rear floor 2A as a load. The tool box 20 has recesses 21, 22, 23, 24, 25 that open upward, and in-vehicle parts 21A, 22A, 23A, 24A, 25A housed in these recesses 21, 22, 23, 24, 25. The recess 21 constitutes the recess in the present invention. The in-vehicle part 21A constitutes the in-vehicle part in the present invention. Here, the in-vehicle part 21A is a pantograph-type jack for raising and lowering the vehicle 1, and is stored in the recess 21 in a lying state with the rotation axis during raising and lowering facing in the vehicle longitudinal direction. Behind the frame unit 30 on the rear floor 2A, in addition to the tool box 20, loads such as luggage not shown may be placed.

[0022] In FIG. 3, the battery pack 10 has a battery main body 10A and a battery case 11 that covers the battery main body 10A. The battery case 11 has a lower case 13 that covers the battery main body 10A from below and an upper case 12 that covers the battery main body 10A from above. The lower end portion of the upper case 12 is joined to the upper end portion of the lower case 13 at the position of the side surface of the battery main body 10A. The L-shaped bracket 46 is fixed to the lower case 13 that constitutes the lower portion of the battery case 11.

[0023] The upper cross frame 33 is positioned above the lower cross frame 34 in the vertical direction of the vehicle, and behind the battery pack 10 and in front of the lower cross frame 34 in the longitudinal direction of the vehicle. The rear bracket 39 has an upper bracket 39A fixed to the upper cross frame 33 and a lower bracket 39B fixed to the lower cross frame 34. The lower bracket 39B extends linearly upward from the lower cross frame 34. The upper bracket 39A extends diagonally downward and rearward from the upper cross frame 33. The rear bracket 39 also has a joint portion 39C where the upper bracket 39A and the lower bracket 39B overlap and are joined to each other in the longitudinal direction of the vehicle.

[0024] The joint 39C consists of an upper bracket side joint 39A1 that extends rearward from the lower end of the upper bracket 39A, and a lower bracket side joint 39B1 that extends forward from the upper end of the lower bracket 39B and overlaps with the upper bracket side joint 39A1. At the joint 39C, the upper bracket side joint 39A1 and the lower bracket side joint 39B1 are fixed together by bolts 47.

[0025] A lower case side flange portion 13A is formed at the upper end of the rear surface of the lower case 13, extending toward the rear of the vehicle and connecting to the upper case 12. An upper case side flange portion 12A is formed at the lower end of the rear surface of the upper case 12, extending toward the rear of the vehicle and connecting to the lower case side flange portion 13A.

[0026] In Figures 3, 4, and 5, the upper case flange portion 12A has an extended portion 12B that extends rearward from the lower case flange portion 13A. In Figure 4, the lower case flange portion 13A is hidden below (behind on the page) the upper case flange portion 12A and is represented by a dashed line.

[0027] The joint portion 39C is positioned at the same location as the extension portion 12B in the vertical direction of the vehicle, and faces the extension portion 12B in the longitudinal direction of the vehicle.

[0028] The upper case 12 is made of a material that is more easily deformed compared to the lower case 13. For example, the upper case 12 has lower rigidity than the lower case 13 and is made of a different type of material than the lower case 13, or, even if it is the same type of material as the lower case 13, it is made of a thinner material.

[0029] In Figure 5, the lower case side flange portion 13A has a plurality of boss portions 13B arranged in the vehicle width direction, to which bolts 14 passing through the upper case side flange portion 12A are fastened.

[0030] The extension portion 12B is positioned between two adjacent boss portions 13B in the vehicle width direction on the upper case side flange portion 12A.

[0031] As described above, in this embodiment, the frame unit 30 includes a lower cross frame 34 extending in the vehicle width direction behind and below the battery pack 10, an upper cross frame 33 extending in the vehicle width direction behind and above the battery pack 10, and a rear bracket 39 extending in the vehicle vertical direction behind the battery pack 10 and connected to the lower cross frame 34 and the upper cross frame 33. The battery pack 10 includes a battery body 10A and a battery case 11 that covers the battery body 10A. The battery case 11 includes a lower case 13 that covers the battery body 10A from below, and an upper case 12 that covers the battery body 10A from above and is connected to the lower case 13. A lower case side flange portion 13A is formed at the upper end of the rear surface of the lower case 13, extending towards the rear of the vehicle and connecting to the upper case 12. An upper case side flange portion 12A is formed at the lower end of the rear surface of the upper case 12, extending towards the rear of the vehicle and connecting to the lower case side flange portion 13A. The upper case side flange portion 12A has an extension portion 12B that extends further rearward than the lower case side flange portion 13A. The rear bracket 39 has an upper bracket 39A fixed to the upper cross frame 33, a lower bracket 39B fixed to the lower cross frame 34, and a joint portion 39C to which the upper bracket 39A and the lower bracket 39B overlap and are joined to each other in the vehicle's longitudinal direction. The joint portion 39C is positioned at the same location as the extension portion 12B in the vehicle's vertical direction and faces the extension portion 12B in the vehicle's longitudinal direction.

[0032] As a result, when vehicle 1 is involved in a rear-end collision, cargo such as luggage placed on the rear floor 2A of the luggage compartment 2B moves forward and collides with the rear bracket 39. As shown in Figure 6, when the joint 39C of the rear bracket 39 moves forward and contacts the extension 12B, the extension 12B deforms appropriately, absorbing the load from the joint 39C. Therefore, the distance D in the vehicle's longitudinal direction from the extension 12B can be used as a crushable zone, while preventing the impact of the rear-end collision of vehicle 1 from acting on the battery pack 10. As a result, the battery pack 10 can be protected from the impact force of the rear-end collision of vehicle 1.

[0033] Furthermore, in this embodiment, the upper case 12 is made of a material that is more easily deformed compared to the lower case 13.

[0034] This allows the expanded portion 12B of the upper case side flange portion 12A to deform appropriately, thereby absorbing the impact during a rearward collision of the vehicle 1.

[0035] In this embodiment, the on-board component 21A is mounted behind the frame unit 30 on the rear floor 2A.

[0036] As a result, when vehicle 1 is involved in a rear-end collision, if the onboard component 21A moves forward and collides with the rear bracket 39, and the joint portion 39C of the rear bracket 39 moves forward and contacts the extension portion 12B, the extension portion 12B can deform appropriately to absorb the load from the joint portion 39C. Therefore, the distance D in the vehicle's longitudinal direction from the extension portion 12B can be used as a crushable zone, while preventing the impact of the rear-end collision of vehicle 1 from acting on the battery pack 10. In this way, the battery pack 10 can be protected from the impact force of the rear-end collision of vehicle 1.

[0037] In this embodiment, a toolbox 20 is placed behind the frame unit 30 on the rear floor 2A, having an upwardly opening recess 21 and on-board components 21A housed in the recess 21.

[0038] As a result, when vehicle 1 is hit from behind, the toolbox 20 containing the onboard components 21A moves forward and collides with the rear bracket 39, and the joint 39C of the rear bracket 39 moves forward and contacts the extension 12B. In this case, the extension 12B deforms appropriately, absorbing the load from the joint 39C. Therefore, the distance D in the vehicle's longitudinal direction from the extension 12B can be used as a crushable zone, while preventing the impact of vehicle 1's rear collision from acting on the battery pack 10. Furthermore, the front part of the toolbox 20 is compressed front to back by being sandwiched between the onboard components 21A and the rear bracket 39, thereby absorbing the impact. As a result, the battery pack 10 can be protected from the impact force of vehicle 1's rear collision.

[0039] In this embodiment, the lower case flange portion 13A has a plurality of boss portions 13B arranged in the vehicle width direction, to which bolts 14 passing through the upper case flange portion 12A are fastened. The extension portion 12B is positioned between two adjacent boss portions 13B in the vehicle width direction on the upper case flange portion 12A.

[0040] As a result, even if the extension portion 12B is significantly deformed, the highly rigid boss portion 13B of the lower case side flange portion 13A can bear the load from the rear, thereby preventing further deformation of the battery case 11 and protecting the battery body 10A inside the battery case 11. In other words, after the extension portion 12B is significantly deformed, the boss portion 13 can protect the battery body 10A. Therefore, it is no longer necessary to design the extension portion 12B to protrude significantly to the rear, and the size of the battery case 11 can be prevented from increasing.

[0041] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of symbols]

[0042] 1 vehicle 2A Rear Floor 2B Luggage compartment 10 Battery Packs 10A Battery Unit 11 Battery Case 12 Upper Case 12A Upper case side flange 12B Expansion Section 13 Lower Case 13A Lower case side flange section 13B Boss Section 14 volts 20 Toolboxes 21 Recess 21A Automotive parts 30 Frame Units 33 Upper Cross Frame 34 Lower Cross Frame 39 Rear Bracket (Bracket) 39A Upper Bracket 39B Lower Bracket 39C joint

Claims

1. The battery pack is located on the rear floor of the luggage compartment at the rear of the vehicle, A battery pack protection structure in a vehicle comprising a frame unit that surrounds the battery pack with a plurality of interconnected frames and is fixed to the rear floor, The frame unit comprises a lower cross frame extending in the vehicle width direction behind and below the battery pack, an upper cross frame extending in the vehicle width direction behind and above the battery pack, and a bracket extending in the vehicle vertical direction behind the battery pack and connected to the lower cross frame and the upper cross frame. The aforementioned battery pack comprises a battery body and a battery case that covers the battery body. The battery case comprises a lower case that covers the battery body from below, and an upper case that covers the battery body from above and is connected to the lower case. A lower case side flange portion is formed at the upper end of the rear surface of the lower case, extending toward the rear of the vehicle and connecting to the upper case. An upper case side flange portion is formed at the lower end of the rear surface of the upper case, extending toward the rear of the vehicle and connecting to the lower case side flange portion. The upper case side flange portion has an extended portion that extends further rearward than the lower case side flange portion. The bracket comprises an upper bracket fixed to the upper cross frame, a lower bracket fixed to the lower cross frame, and a joint portion to which the upper bracket and the lower bracket are joined together while overlapping and extending in the longitudinal direction of the vehicle. The battery pack protection structure is characterized in that the joint portion is positioned at the same location as the extension portion in the vertical direction of the vehicle and faces the extension portion in the front-rear direction of the vehicle.

2. The battery pack protection structure according to claim 1, characterized in that the upper case is made of a material that is more easily deformed than the lower case.

3. The battery pack protection structure according to claim 1, characterized in that an in-vehicle component is placed behind the frame unit on the rear floor.

4. The battery pack protection structure according to claim 3, characterized in that a toolbox having an upwardly opening recess and the vehicle components housed in the recess is placed behind the frame unit on the rear floor.

5. The lower case side flange portion has a plurality of boss portions arranged in the vehicle width direction, through which bolts passing through the upper case side flange portion are fastened. The battery pack protection structure according to claim 1 or 2, characterized in that the extended portion is positioned between two adjacent boss portions in the vehicle width direction on the upper case side flange portion.

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