Battery pack mounting structure

Abstract

Provided is a structure for mounting a battery pack to be fixed on an underside of a floor of a vehicle, the structure comprising: a case that accommodates the battery; a first through-hole provided in a lower member of the case; a second through-hole provided in an upper member of the case; a first member having a tube member inserted through the first through-hole and the second through-hole; a second member having a third through-hole through which the tube member is inserted; and a bolt that is inserted through the tube member and fastened to a vehicle body of the vehicle, wherein the first member has a flange, which is disposed on the lower member side of the case and to which the tube member is connected, and a first seal portion, which is disposed around the tube member and seals a gap between a periphery of the first through-hole and the flange.

Description

Technical Field

[0001] The present disclosure relates to an attachment structure of a battery pack.

Background Art

[0002] Conventionally, a battery pack mounted on an electric vehicle has been known (for example, see Patent Document 1). The battery pack of Patent Document 1 extends a bracket from the upper lid of the case that houses the battery, and fixes the battery pack to the vehicle body via the bracket.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, electric vehicles have been required to increase the cruising range by the motor. For this reason, it is required to make the volume inside the case of the battery pack as large as possible. The attachment structure of the battery pack of Patent Document 1 requires tightening a bolt inserted through the bracket. For this reason, the battery pack of Patent Document 1 needs to provide a space for a tool to access the bracket portion. Due to this space, the battery pack of Patent Document 1 cannot provide a case below the bracket, and the volume inside the case decreases.

[0005] An object of the present disclosure is to provide an attachment structure of a battery pack that can fasten a bolt by passing through the case from the lower surface of the case.

Means for Solving the Problems

[0006] The battery pack mounting structure according to this disclosure is a battery pack mounting structure fixed to the underside of the floor of a vehicle, comprising: a case for housing a battery; a first through hole provided in the lower member of the case; a second through hole provided in the upper member of the case; a first member having a cylindrical member inserted through the first through hole and the second through hole; a second member having a third through hole through which the cylindrical member is inserted; and a bolt inserted through the cylindrical member for fastening to the vehicle body, wherein the first member is disposed on the lower member side of the case and has a flange to which the cylindrical member is connected; and a first sealing portion disposed around the cylindrical member and sealing the space between the periphery of the first through hole and the flange.

[0007] This battery pack mounting structure allows bolts to pass through from the bottom to the top of the battery pack. Furthermore, this battery pack prevents water from entering through the through-holes thanks to the first seal. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a battery pack that can be fastened to the vehicle body with bolts that pass through the case from the lower member of the case. [Brief explanation of the drawing]

[0009] [Figure 1] A diagram showing the understructure of a vehicle according to one embodiment of the present disclosure. [Figure 2] A top view of a battery pack according to one embodiment of the present disclosure. [Figure 3] A cross-sectional view of a battery pack mounting structure according to one embodiment of the present disclosure. [Figure 4] Enlarged view of section A in Figure 3. [Figure 5] A perspective view showing the upper surface structure of the first member and the second member according to one embodiment of the present disclosure. [Figure 6] A perspective view showing the lower surface structure of the first member and the second member according to one embodiment of the present disclosure. [Figure 7]A perspective view showing a first reinforcing member and a second reinforcing member according to one embodiment of the present disclosure. [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 Figure 1, the battery pack mounting 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 E2 through which the exhaust of an internal combustion engine E1 passes. The battery pack P is composed of a secondary battery such as a lithium-ion battery, and a battery module, which is a collection of multiple battery cells, is arranged inside.

[0012] As shown in Figures 1, 2, 3, and 4, the battery pack mounting structure 1 comprises a case 2, a lower through-hole (see Figure 1, an example of a first through-hole) 4, an upper through-hole (see Figure 2, an example of a second through-hole) 6, a first member (see Figures 3 and 4) 8, a second member (see Figures 3 and 4) 10, a bolt 12, a plurality of first reinforcing members 14, and a plurality of second reinforcing members 16.

[0013] Case 2 is a component for sealing the battery. As shown in Figure 3, Case 2 has a housing member (an example of a lower member) 2a and a lid member (an example of an upper member) 2b that closes the opening 2c of the housing member 2a. The housing member 2a includes left and right side portions 22, a bottom portion 23 connecting the left and right side portions 22, a plurality of left and right support members 25a extending in the left-right direction (the same as the width direction of the vehicle C, or vehicle width direction) and supporting the housing member 2a, and a plurality of front and rear support members 25b extending in the front-rear direction and supporting the housing member 2a. Brackets 24 are fixed to each of the left and right side portions 22. The brackets 24 are bolted to the side members C2 of the vehicle C. The housing member 2a in this embodiment is a sheet metal member formed by press molding a plate-shaped metal.

[0014] The housing member 2a has a tunnel section 3 at the bottom 23, which bulges in an arch shape toward the upper side U of the vehicle C. As shown in Figure 1, the tunnel section 3 extends in the longitudinal direction of the vehicle C. The exhaust pipe E2 passes through the tunnel section 3. The bottom 23 has an upper surface 23a and a lower surface 23b. Figure 1 shows the lower surface 23b of the bottom 23. As shown in Figure 3, the bottom 23 has a saddle-shaped cross-section with the tunnel section 3 formed approximately in the center in the left-right direction.

[0015] As shown in Figures 2 and 3, the lid member 2b has an upper surface 26a, a lower surface 26b, a protrusion 26c, and a plurality of ribs 26d. As shown in Figure 2, the plurality of ribs 26d extend in the left-right direction, and the upper surface 26a is recessed to the upper side U or lower side D, thereby reinforcing the lid member 2b. The protrusion 26c is a portion of the upper surface 26a of the lid member 2b that bulges upward to match the shape of the tunnel section 3. As shown in Figure 3, the lid member 2b of this embodiment is a sheet metal member formed by press molding a plate-shaped metal.

[0016] As shown in FIGS. 1 and 4, the lower through-hole 4 is provided in the housing member 2a of the case 2. The lower through-hole 4 penetrates from the upper surface 23a to the lower surface 23b of the housing member 2a. As shown in FIG. 1, the lower through-hole 4 is provided substantially at the center in the left-right direction and the front-rear direction. In the present embodiment, the lower through-hole 4 has an oval shape that is long in the left-right direction of the battery pack P. As shown in FIG. 4, the lower through-hole 4 is provided in the tunnel portion 3 and penetrates from the upper surface 23a to the lower surface 23b of the tunnel portion 3.

[0017] As shown in FIGS. 2 and 4, the upper through-hole 6 is provided in the lid member 2b of the case 2. The lower through-hole 4 penetrates from the lower surface 23b to the upper surface 23a of the housing member 2a. As shown in FIG. 4, the upper through-hole 6 is provided at the same position as the lower through-hole 4 in the front-rear direction and the left-right direction of the vehicle. As shown in FIG. 2, the upper through-hole 6 is provided substantially at the center in the left-right direction and the front-rear direction of the battery pack P, similarly to the lower through-hole 4. In the present embodiment, the upper through-hole 6 has an oval shape that is long in the left-right direction. As shown in FIG. 4, the upper through-hole 6 penetrates from the upper surface 26a to the lower surface 26b of the convex portion 26c of the lid member 2b.

[0018] The first member 8 is disposed substantially at the center in the left-right direction and the front-rear direction of the battery pack P in accordance with the position of the lower through-hole 4. In the present embodiment, the first member 8 is disposed on the lower surface 23b side of the tunnel portion 3 of the housing member 2a. The first member 8 is a member having a cylindrical member 30 that is inserted into the lower through-hole 4 and the upper through-hole 6. As shown in FIG. 5, the cylindrical member 30 and the first member 8 have a flange 31, a first seal portion 32, a third seal portion 33, an O-ring 34, and a plurality of bolt through-holes 35. In the present embodiment, the first member 8 is a metal member or a resin member.

[0019] As shown in FIG. 4, the cylindrical member 30 is a member having a length that extends from the lower surface 23b of the housing member 2a beyond the upper surface 26a of the lid member 2b. In the present embodiment, the cylindrical members 30 are two cylindrical members arranged side by side in the left - right direction. That is, the battery pack P is fixed at the center by two bolts 12 arranged side by side in the left - right direction. The flange 31 is a member having an upper surface 31a to which the cylindrical member 30 is connected and which is larger than the lower through - hole 4. The flange 31 contacts the lower surface 23b of the housing member 2a via the third seal portion 33 and supports the lower surface 23b in a state where the bolt 12 is tightened.

[0020] As shown in FIG. 5, the first seal portion 32 is arranged around the cylindrical member 30. In the present embodiment, the first seal portion 32 is formed by attaching a seal member made of rubber or resin to a groove formed in the flange 31. The first seal portion 32 is formed along the shape of the lower through - hole 4. The first seal portion 32 seals between the periphery of the lower through - hole (see FIG. 4) 4 of the lower surface 23b of the housing member 2a and the upper surface 31a of the flange 31. Thereby, it prevents water from entering the inside of the battery pack P from the lower through - hole 4.

[0021] The third seal portion 33 is formed around the upper surface 31a of the flange 31. The third seal portion 33 is a dust seal formed of rubber or resin. As shown in FIG. 4, the third seal portion 33 seals between the upper surface 31a of the flange 31 and the lower surface 23b of the housing member 2a, and prevents dust from entering around the first seal portion 32.

[0022] As shown in FIG. 5, the plurality of bolt through - holes 35 are arranged around the flange 31. In the present embodiment, the flange 31 is substantially square and is arranged at the four corners of the flange 31. As shown in FIG. 4, a weld bolt (not shown) fixed to the lower surface 23b of the housing member 2a is inserted through the bolt through - hole 35. The nut 36 is coupled to the weld bolt and tightens the flange 31.

[0023] The second member 10 is positioned approximately in the center of the battery pack P in the front-to-back and left-to-right directions, aligned with the position of the upper through-hole 6. In this embodiment, the second member 10 is positioned on the upper surface 26a side of the protrusion 26c of the lid member 2b. The second member 10 is a member having a through-hole (an example of a third through-hole) 40 through which the cylindrical member 30 is inserted. As shown in Figure 6, the second member 10 has a through-hole 40, a flange 41, a second sealing portion 42, a fourth sealing portion 43, and a plurality of bolt through-holes 44. In this embodiment, the second member 10 is a metal member or a resin member.

[0024] The through-hole 40 penetrates from the upper surface 41a to the lower surface 41b of the flange 41. The number of through-holes 40 corresponds to the number of cylindrical members 30. In this embodiment, two are formed side by side in the left-right direction. The through-hole 40 has a diameter slightly larger than the diameter of the cylindrical member 30. In this embodiment, the through-hole 40 is the inner circumferential surface of the cylindrical member extending from the upper surface 41a of the flange 41. As shown in Figure 4, the O-ring 34 contacts this inner circumferential surface, thereby sealing the outer circumferential surface of the cylindrical member 30 and the inner circumferential surface of the through-hole 40. This prevents water from entering the inside of the battery pack P from the outer circumference of the cylindrical member 30.

[0025] As shown in Figure 6, the second seal portion 42 is positioned around the through hole 40. In this embodiment, the second seal portion 42 is formed by attaching a sealing member made of rubber or resin to a groove formed in the flange 41. As shown in Figure 4, the second seal portion 42 is formed along the shape of the upper through hole 6. The second seal portion 42 seals the space between the upper surface 26a of the lid member 2b around the upper through hole 6 and the lower surface 41b of the flange 41. As a result, the second seal portion 42, together with the O-ring 34, seals the space between the cylindrical member 30 and the upper through hole 6. This prevents water from entering the inside of the battery pack P through the upper through hole 6.

[0026] As shown in Figure 6, the fourth sealing portion 43 is formed around the lower surface 41b of the flange 41. The fourth sealing portion 43 is a dust seal made of rubber or resin. As shown in Figure 4, the fourth sealing portion 43 seals the space between the upper surface 41a of the flange 41 and the upper surface 26a of the lid member 2b, preventing dust from entering around the second sealing portion 42.

[0027] As shown in Figure 6, multiple bolt holes 44 are arranged around the flange 41. In this embodiment, the flange 41 is approximately rectangular, and the bolt holes are located at the four corners of the flange 41. As shown in Figure 4, weld bolts (not shown) fixed to the upper surface 26a of the cover member 2b are inserted through the bolt holes 44. Nuts 45 are connected to the weld bolts and tighten the flange 41.

[0028] As shown in Figures 3 and 4, the bolt 12 passes through the cylindrical member 30 and is fastened to the vehicle body member C3 of the vehicle C. The vehicle body member C3 is a structural member located between a pair of side members C2 and extending in the left-right direction. The vehicle body member C3 is, for example, a cross member.

[0029] As shown in Figure 3, the first reinforcing member 14 is a member that extends along the shape of the lower surface 23b of the tunnel section 3. As shown in Figure 1, in this embodiment, three first reinforcing members 14 are arranged in a row in the front-rear direction. The lower through hole 4 and the first member 8 are positioned offset from the first reinforcing member 14 in the front-rear direction when viewed from the lower side D. As shown in Figure 7, the first 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 3. The rib 14a is provided protruding toward the lower side D of the tunnel section 3. 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. The first reinforcing member 14 is a sheet metal member formed by press molding of a plate-shaped metal member.

[0030] As shown in Figure 4, the first member 8 is positioned in the tunnel section 3. The bolt 12 that passes through the cylindrical member 30 of the first member 8 has its lower end 12a positioned above the lower end 14e of the rib 14a of the first reinforcing member 14. This makes it difficult for heat generated from the exhaust pipe E2 to reach the first member 8.

[0031] As shown in Figure 3, the flange 14c of the first reinforcing member 14 is welded to the lower surface 23b of the housing member 2a. The flange 14d of the first reinforcing member 14 is welded to the lower surface 23b of the tunnel section 3. A weld bolt is inserted through the through hole 14b of the first reinforcing member 14.

[0032] As shown in Figure 3, the second reinforcing member 16 extends in the left-right direction of the vehicle C and is fixed to the lower surface 23b of the housing member 2a. In this embodiment, the second reinforcing member 16 is arranged to overlap the first reinforcing member 14 in the vertical direction. As shown in Figure 7, the second reinforcing member 16 is a sheet metal member with a U-shaped cross-section and an opening facing downwards. The second reinforcing member 16 has a rib 16a, a through hole 16b, and a flange 16c. The rib 16a is provided in the center of the second reinforcing member 16 and is a portion that protrudes downwards D. The through hole 14b is provided at the left and right ends of the second reinforcing member 16 and penetrates the second reinforcing member 16. In this embodiment, there are two through holes 16b at each of the left and right ends, for a total of four. The flange 16c is provided around the second reinforcing member 16. The second reinforcing member 16 is fixed to the housing member 2a by inserting a weld bolt, which is welded to the housing member 2a, through the through hole 16b and tightening the weld bolt with a nut.

[0033] The weight of the battery is concentrated near the center of the housing member 2a of the battery pack P. Therefore, stress tends to concentrate near the center of the battery pack P. In particular, if the battery pack P has a tunnel section 3 in the left-right direction, stress concentration is even more likely to occur.

[0034] However, the battery pack mounting structure 1 allows bolts 12 to pass through from the lower surface 23b to the upper surface 26a of the battery pack P. When the bolts 12 are fastened to the vehicle body member C3, the approximate center of the battery pack P is supported by the vehicle body member C3. This allows the battery pack mounting structure 1 to alleviate stress concentration near the center of the battery pack P. Furthermore, with this battery pack mounting structure 1, the worker installing the battery pack P can easily access the bolts 12 from the lower side D of the battery pack P. This makes the battery pack mounting structure 1 easy to work with.

[0035] Furthermore, with this battery pack mounting structure 1, the first member 8 and the second member 10 can be used to seal the area around the lower through-hole 4 and the upper through-hole 6 of the battery pack P. This ensures that the battery pack P remains airtight.

[0036] As described above, this disclosure provides a mounting structure 1 for a battery pack P that allows a bolt 12 to be fastened to a vehicle body member C3 by passing through the case 2 from the lower member of the case 2.

[0037] <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.

[0038] (a) In the above embodiment, a battery pack P having a tunnel portion 3 was used for the description, but the disclosure is not limited thereto. The battery pack P may be a battery pack that does not have a tunnel portion 3.

[0039] (b) In the above embodiment, an example was described in which two bolts 12 arranged in the left-right direction are fastened to the vehicle body member C3, but the disclosure is not limited thereto. The number and arrangement of the bolts 12 may be changed as appropriate to suit the shape of the battery pack P.

[0040] (c) In the above embodiment, the first member 8 and the second member 10 were positioned approximately in the center of the battery pack P in the left-right and front-back directions, and the bolts 12 were fixed to them. However, the disclosure is not limited thereto. The position of the bolts 12 can be appropriately positioned according to the load applied to the battery pack P. [Explanation of Symbols]

[0041] 1: Mounting structure, 2: Case, 2a: Storage member, 2b: Lid member 3: Tunnel section 4: Lower through hole, 6: Upper through hole 8: First member, 10: Second member, 12: Bolt, 12a: Lower end 14: First reinforcing member 30: cylindrical member, 31: flange, 32: first seal part, 33: third seal part 34: O-ring 40: Through hole, 41: Flange, 42: Second seal section, 43: Fourth seal section C: Vehicle, C1: Floor, C3: Body components P: Battery pack

Claims

1. A mounting structure for a battery pack that is fixed to the underside of the vehicle floor, A case that houses the battery, A first through-hole is provided in the lower member of the case, A second through-hole is provided in the upper member of the case, A first member having a cylindrical member inserted through the first through hole and the second through hole, A second member having a third through-hole through which the cylindrical member is inserted, A bolt inserted through the cylindrical member and fastened to the vehicle body, Equipped with, The first member is, A flange is positioned on the lower side of the case and to which the cylindrical member is connected, It has a first sealing portion that is arranged around the cylindrical member and seals the space between the periphery of the first through hole and the flange, The second member has a second sealing portion that seals the space between the second through hole and the cylindrical member. Battery pack mounting structure.

2. A mounting structure for a battery pack that is fixed to the underside of the vehicle floor, A case that houses the battery, A first through-hole is provided in the lower member of the case, A second through-hole is provided in the upper member of the case, A first member having a cylindrical member inserted through the first through hole and the second through hole, A second member having a third through-hole through which the cylindrical member is inserted, A bolt inserted through the cylindrical member and fastened to the vehicle body, Equipped with, The first member is, A flange is positioned on the lower side of the case and to which the cylindrical member is connected, The cylindrical member has a first sealing portion arranged around it that seals the space between the first through-hole and the flange, and a third sealing portion arranged around the flange that seals the space between the lower member of the case and the flange. Battery pack mounting structure.

3. The case extends in the longitudinal direction of the vehicle, and the lower member has a tunnel section that bulges in an arch shape upward toward the vehicle. The tunnel section is further provided with reinforcing members that are arranged in the tunnel section and reinforce the tunnel section, The first member is arranged in the tunnel section, The lower end of the bolt is located above the lower end of the reinforcing member. A battery pack mounting structure according to claim 1 or 2.

Images