Battery pack structure

Abstract

This battery pack structure is a structure of a battery pack disposed on an under side of a floor of a vehicle, the structure comprising: an accommodation member that accommodates a battery; a tunnel portion extending in the front–rear direction of the vehicle and bulging in an arch shape in cross section from a bottom surface of the accommodation member toward the upper side of the vehicle; a pair of recessed portions formed adjacent to the tunnel portion in the width direction of the vehicle; and a first reinforcing member extending in the vehicle width direction of the vehicle and fixed to the pair of recessed portions. A lower end of the first reinforcing member is located at the same position as the bottom surface or on an upper side from the bottom surface as viewed in the top-down direction.

Description

Technical Field

[0001] This disclosure relates to a battery pack structure.

Background Art

[0002] 999>Conventionally, a battery pack disposed under the floor of a vehicle is known (see, for example, Patent Document 1). The battery pack of Patent Document 1 has a structure with a tunnel portion in the central portion in the vehicle width direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a battery pack structure having a tunnel portion, it is preferable to reinforce the tunnel portion. In the battery pack structure of Patent Document 1, in order to reinforce the tunnel portion, a frame member is disposed below the tunnel portion. For this reason, the ground clearance of the vehicle decreases.

[0005] An object of this disclosure is to provide a battery pack structure capable of reinforcing the tunnel portion of a battery pack without lowering the ground clearance.

Means for Solving the Problems

[0006] The battery pack structure according to this disclosure is a battery pack structure disposed on the underside of the floor of a vehicle, comprising: a housing member for housing a battery; a tunnel portion extending in the longitudinal direction of the vehicle and bulging in an arch shape in cross-section from the lower surface of the housing member toward the upper side of the vehicle; a pair of recesses formed adjacent to the tunnel portion in the width direction of the vehicle; and a first reinforcing member extending in the vehicle width direction of the vehicle and fixed to the pair of recesses, wherein the lower end of the first reinforcing member is located at the same position as the lower surface or above the lower surface when viewed in the vertical direction.

[0007] In this battery pack structure, the lower surface of the housing member and the lower end of the reinforcing member are at the same position, or the lower surface is located lower, when viewed in the vertical direction. As a result, the ground clearance is not reduced by the first reinforcing member. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a battery pack structure that can reinforce the tunnel portion of the battery pack without reducing the ground clearance. [Brief explanation of the drawing]

[0009] [Figure 1] A bottom view of a battery pack structure according to one embodiment of the present disclosure. [Figure 2] A top view of a housing member according to one embodiment of the present disclosure. [Figure 3] Cross-sectional view AA in Figure 1. [Figure 4] Figure 3 shows a magnified view of the area near the tunnel. [Figure 5] A diagram showing the first and second reinforcing members. [Modes for carrying out the invention]

[0010] Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. In the following specification and drawings, the right side of vehicle C in the direction of travel will be denoted as R, the left side as L, the front side as F, the rear side as B, the upper side as U, and the lower side as D.

[0011] As shown in Figures 1, 2, and 3, the battery pack structure 1 comprises a housing member 2, a tunnel section 4, a recess 6, a first wall member 8, a second wall member 10, a third wall member 11, a first reinforcing member 12, a second reinforcing member 14, a third reinforcing member 16, and a fourth reinforcing member 17.

[0012] As shown in Figure 1, the battery pack structure 1 of this disclosure is the structure of a battery pack P located on the underside D of the floor C1 of a vehicle C. The vehicle C of this disclosure is a plug-in hybrid vehicle (PHEV) capable of external charging or external power supply. The vehicle C has an exhaust pipe 20 through which the exhaust of an internal combustion engine 18 passes, and the exhaust pipe 20 passes through a tunnel section 4.

[0013] The housing member 2 is a member for housing the battery. In this embodiment, the housing member 2 is a sheet metal member formed by press molding a plate-shaped metal. As shown in Figure 3, a lid member 3 is placed on the upper part of the housing member 2 to close the opening of the housing member 2 and seal the inside of the housing member 2. The housing member 2 has left and right side portions 22 and a bottom portion 23 that connects the left and right side portions 22 to each other. Brackets 24 are fixed to each of the left and right side portions 22. The brackets 24 are fixed to the side member C2 of the vehicle C with bolts.

[0014] The bottom portion 23 has an upper surface 23a and a lower surface 23b. Figure 1 shows the lower surface 23b of the bottom portion 23. Figure 2 shows the upper surface 23a. As shown in Figure 3, the bottom portion 23 has a saddle-shaped cross-section with a tunnel portion 4 formed approximately in the center in the left-right direction.

[0015] The tunnel section 4 is the portion where the cross-section of the bottom 23 bulges out in an arch shape from the lower surface 23b toward the upper side U of the vehicle C. As shown in Figures 1 and 2, the tunnel section 4 extends in the longitudinal direction of the vehicle C.

[0016] As shown in FIG. 1, the recess 6 is a portion where the bottom 23 is recessed toward the upper side U of the vehicle C. The recesses 6 are arranged in a pair adjacent to the left and right of the tunnel portion 4 at positions where the first reinforcing member 12 is provided. In the present embodiment, a total of six recesses 6 are arranged in accordance with the positions and numbers of the first wall members 8 and the first wall members 8. As shown in FIG. 4, the recess 6 has a bottom surface 6a and an inclined surface 6b. The bottom surface 6a is a surface formed at a position recessed upward U from the lower surface 23b of the bottom 23. The inclined surface 6b is a surface extending from the bottom surface 6a toward the lower surface 23b.

[0017] As shown in FIG. 2, the first wall member 8 is a member extending in the left - right direction (also referred to as the vehicle width direction). In the present embodiment, the first wall member 8 is a sheet metal member having a rectangular cross - section and is spot - welded to the upper surface 23a of the bottom 23. By fixing the first wall member 8 to the bottom 23, the rigidity of the bottom 23 in the left - right direction is increased. In the present embodiment, the first wall members 8 are arranged in three rows, two in each row, for a total of six.

[0018] As shown in FIG. 1, the recess 6 is arranged at a position overlapping the first wall member 8 when viewed in the front - rear direction of the vehicle C. More specifically, the width of the recess 6 in the front - rear direction overlaps the width of the first wall member 8 in the front - rear direction. In the present embodiment, the width of the recess 6 in the front - rear direction is smaller than the width of the first wall member 8 in the front - rear direction.

[0019] As shown in FIG. 2, the second wall member 10 is arranged along the tunnel portion 4 and extends in the front - rear direction of the vehicle C. The second wall member 10 covers the upper surface 23a of the tunnel portion 4. As shown in FIG. 4, in the present embodiment, the second wall member 10 is a sheet metal member having a Z - shaped cross - section. The second wall member 10 is spot - welded to the upper surface 23a of the bottom 23, the upper surface 23a of the recess 6, and the upper surface 23a of the tunnel portion 4. By fixing the second wall member 10 to the bottom 23, the rigidity of the tunnel portion 4 in the front - rear direction is increased. Also, the second wall member 10 is welded and fixed to the first wall member 8. In the present embodiment, the second wall members 10 are arranged one on each side of the left and right of the tunnel portion 4.

[0020] As shown in FIG. 2, the third wall member 11 is a member that is arranged along the left and right side portions 22 and extends in the front-rear direction. As shown in FIG. 3, the third wall member 11 is a sheet metal member having a Z-shaped cross section. The third wall member 11 is spot-welded to the upper surface 23a of the bottom portion 23 and the side portions 22. By fixing the third wall member 11 to the upper surface 23a of the bottom portion 23 and the side portions 22, the rigidity of the side portions 22 in the front-rear direction is increased. The third wall member 11 is welded and fixed to the first wall member 8. In the present embodiment, one third wall member 11 is arranged on each of the left and right side portions 22.

[0021] As shown in FIG. 5, the first reinforcing member 12 extends in the left-right direction of the vehicle C and is fixed to the pair of recesses 6. In the present embodiment, three rows of left and right pairs of recesses 6 are arranged, and the first reinforcing member 12 is arranged in the recesses 6. As shown in FIG. 4, the first reinforcing member 12 is a sheet metal member having a U-shaped cross section with an opening facing downward. The first reinforcing member 12 has a rib 12a, a through hole 12b, and a flange 12c. The rib 12a is provided at the central portion of the first reinforcing member 12 and is a portion that protrudes toward the lower side D. The through holes 12b are provided at the left and right ends of the first reinforcing member 12 and penetrate the first reinforcing member 12. In the present embodiment, two through holes 12b are arranged at each of the left and right ends, for a total of four. The flange 12c is provided around the first reinforcing member 12.

[0022] As shown in FIG. 4, both ends of the first reinforcing member 12 are fixed to the recesses 6. In the present embodiment, a weld bolt 26 is welded and fixed to the bottom surface 6a of the recess 6. The weld bolt 26 is inserted into the through hole 12b (see FIG. 5). The first reinforcing member 12 is fixed to the recess 6 by tightening a nut on the inserted weld bolt. At this time, the lower end of the flange 12c is located at the same position as the lower surface 23b or above the lower surface 23b in the vertical direction U. Further, in a state where the first reinforcing member 12 is fixed to the recess 6, the flange 12c of the first reinforcing member 12 faces the inclined surface 6b of the recess 6 and extends along the inclined surface 6b. Note that the first reinforcing member 12 is fixed to the recess 6 after the exhaust pipe 18 is attached to the vehicle C.

[0023] As shown in Figures 4 and 5, the second reinforcing member 14 is a member that extends along the shape of the lower surface 23b of the tunnel section 4. The second reinforcing member 14 is a sheet metal member formed by press molding a plate-shaped metal member. The second reinforcing member 14 has a rib 14a, a through hole 14b, a pair of left and right flanges (an example of both ends) 14c extending in the left-right direction, and a flange 14d extending along the tunnel section 4. The rib 14a is provided to protrude toward the lower side D of the tunnel section 4. The through hole 14b passes through the pair of left and right flanges 14c. In this embodiment, there are two through holes 14b on each side, for a total of four.

[0024] As shown in Figure 4, the flange 14c of the second reinforcing member 14 is welded to the bottom surface 6a of the recess 6. The flange 14d of the second reinforcing member 14 is welded to the lower surface 23b of the tunnel section 4. A weld bolt is inserted through the through hole 14b of the second reinforcing member 14.

[0025] The third reinforcing member 16 is positioned in the space S2 created between the upper surface 23a of the tunnel section 4 and the second wall member 10. The third reinforcing member 16 is positioned between the vertical wall 10a of the second wall member 10 and the upper surface 23a of the tunnel section 4, and is welded and fixed to these members. This fills the gap in the left-right direction of the space S2. The third reinforcing member 16 is a sheet metal member with an H-shaped or rectangular cross-section. The third reinforcing member 16 is positioned side by side with the first wall member 8 in the left-right direction. Therefore, in this embodiment, three third reinforcing members 16 are positioned side by side in the front-back direction.

[0026] As shown in Figure 3, the fourth reinforcing member 17 is positioned in the space S3 between the third wall member 11 and the side portion 22. The fourth reinforcing member 17 is positioned between the vertical wall 11a of the third wall member 11 and the side portion 22, and is welded and fixed to these members. This fills the gap in the left-right direction of the space S3. The fourth reinforcing member 17 is a sheet metal member with an H-shaped or rectangular cross-section. The fourth reinforcing member 17 is positioned side by side with the first wall member 8 in the left-right direction. Therefore, in this embodiment, three of them are positioned side by side in the front-back direction.

[0027] As shown in Figure 2, in the battery pack structure 1 configured in this way, the battery is arranged in a region X surrounded by a first wall member 8, a second wall member 10, and a third wall member 11. The battery in this embodiment is a battery that drives a motor (not shown) of a vehicle C. The battery is composed of a secondary battery such as a lithium battery, and a battery module, which is a collection of multiple battery cells, is arranged in region X. If the recess 6 overlaps region X, the volume of region X decreases, and the battery module becomes smaller. However, since the recess 6 in this disclosure is positioned to overlap with the first wall member 8 in the front-rear direction, region X and the recess 6 do not overlap. As a result, the recess 6 can be provided while maintaining the volume of region X.

[0028] As shown in Figures 3 and 4, the battery pack structure 1 has a space S1 between the first wall member 8 and the bottom 23 (see Figure 3), a space (an example of a gap) S2 between the upper surface 23a of the tunnel section 4 and the second wall member 10 (see Figure 4), a space S3 between the third wall member 11 and the side 22 (see Figure 3), and a space S4 within the bracket (see Figure 3). In other words, the battery pack structure 1 has four closed sections on each side. This increases the rigidity of the battery pack in the front-rear and left-right directions.

[0029] Furthermore, in this battery pack structure 1, a first reinforcing member 12 and a second reinforcing member 14 are placed in the space below D on the front-rear extension of the tunnel section 4, and a third reinforcing member is placed in spaces S2 and S4 formed in the front-rear direction. A first wall member 8 extends between spaces S2 and S3. This allows the brackets 24 fixed to a pair of side members C2 of the vehicle C to be connected by a structure without interruption. As a result, when the vehicle C is subjected to a side collision, it is possible to suppress the crushing of the battery pack P starting from the tunnel section 4.

[0030] Furthermore, as shown in Figure 4, when the first reinforcing member 12 is fixed in the recess 6, the flange 12c of the first reinforcing member 12 faces the slope 6b of the recess 6 and extends along the slope 6b. This makes it easier to transmit the impact transmitted to the first wall member 8 during a side collision to the first reinforcing member 12. As a result, if a side collision occurs on either the left or right side, the impact is easily transmitted to the other side member C2. Therefore, the impact received by the battery pack P can be mitigated, making it less likely for the battery pack P to be crushed.

[0031] Furthermore, the lower end of the flange 12c is located at the same position as the lower surface 23b or above the lower surface 23b when viewed in the vertical direction. Therefore, the minimum ground clearance of the vehicle C is not compromised.

[0032] As explained above, this disclosure provides a battery pack structure 1 that can reinforce the tunnel portion 4 of the battery pack P without reducing the ground clearance.

[0033] <Other Embodiments> Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. In particular, the various modifications described herein can be combined as needed.

[0034] (a) In the above embodiment, as an example, a pair of recesses 6 are arranged in three rows in the front-rear direction, and three first reinforcing members 12 and second reinforcing members 14 are arranged, but the disclosure is not limited thereto. The number of these members can be appropriately arranged according to the size of the battery pack P.

[0035] (b) In the above embodiment, an example was described in which the exhaust pipe 20 passes through the tunnel section, but the disclosure is not limited thereto. The tunnel section 4 may also pass through a propeller shaft for driving the rear wheels of the vehicle C.

[0036] (c) In the above embodiment, an example was described in which the battery pack P is fixed to the side member C2 of the vehicle C via a bracket 24, but the disclosure is not limited thereto. The battery pack P may be fixed to a structure extending in the longitudinal direction of the vehicle C, other than the side member C2. [Explanation of Symbols]

[0037] 1: Battery pack structure, 2: Housing component, 4: Tunnel section 6: recess, 6a: base, 6b: slope 8: First wall member 10: Second wall member, 10a: Wall 12: First reinforcing member, 12c: Flange 14: Second reinforcing member, 16: Third reinforcing member 23a: Top surface, 23b: Bottom surface C: Vehicle, C1: Floor, P: Battery Pack

Claims

1. The structure of the battery pack located on the underside of the vehicle floor, A housing member for housing the battery, A pair of left and right first wall members are fixed to the upper surface of the housing member and extend in the width direction of the vehicle, A tunnel section extending in the longitudinal direction of the vehicle and bulging in an arch shape from the lower surface of the housing member toward the upper side of the vehicle, A pair of recesses are formed adjacent to the tunnel section and the vehicle in the width direction, and are positioned in accordance with the location of the first wall member, A first reinforcing member extending in the vehicle width direction of the vehicle and fixed to a pair of recesses, Equipped with, The lower end of the first reinforcing member is located at the same position as the lower surface or above the lower surface when viewed in the vertical direction. Battery pack structure.

2. The recesses are arranged in accordance with the number of the first wall members. The battery pack structure according to claim 1.

3. The aforementioned housing member further comprises an area for arranging a battery module that bundles battery cells, The recess is positioned in a location that does not overlap with the region. The battery pack structure according to claim 1.

4. The recess has a bottom surface and a slope extending from the bottom surface toward the lower surface, The first reinforcing member has a flange extending along the slope, The battery pack structure according to claim 1.

5. The system further comprises a second reinforcing member that extends along the lower surface of the tunnel section and whose ends are fixed to a pair of recesses. The battery pack structure according to claim 1.

6. The width of the recess in the front-rear direction is positioned to overlap with the width of the first wall member in the front-rear direction. The battery pack structure according to claim 1.

7. The second wall member is further fixed to the upper surface of the aforementioned housing member and extends in the front-rear direction along the tunnel section, A gap is provided between the second wall member and the upper surface of the tunnel section. The battery pack structure according to any one of claims 1 to 6.

8. The system further comprises a third reinforcing member positioned in the aforementioned gap. The battery pack structure according to claim 7.

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