Structure for mounting battery pack

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

Battery pack mounting structure

[0001] The present disclosure relates to a mounting structure for a battery pack.

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

[0003] JP 2021-60508 A

[0004] In recent years, there has been a demand for electric vehicles to have an increased driving range using their motors. To this end, there is a demand for the volume inside the battery pack case to be as large as possible. The battery pack mounting structure of Patent Document 1 requires that bolts inserted into a bracket be tightened. Therefore, the battery pack of Patent Document 1 requires space for tools to access the bracket. Due to this space, the battery pack of Patent Document 1 cannot mount the case below the bracket, reducing the volume inside the case.

[0005] An object of the present disclosure is to provide a battery pack mounting structure that allows bolts to be fastened by passing through the case from the underside of the case.

[0006] The battery pack mounting structure of the present disclosure is a battery pack mounting structure fixed to the underside of a vehicle floor, and comprises a case that houses a 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 tubular member inserted into the first through hole and the second through hole, a second member having a third through hole through which the tubular member is inserted, and a bolt that is inserted into the tubular member and fastened to the body of the vehicle, wherein the first member is arranged on the lower member side of the case and has a flange to which the tubular member is connected, and a first seal portion that is arranged around the tubular member and seals between the periphery of the first through hole and the flange.

[0007] This battery pack mounting structure allows a bolt to pass through from the bottom surface to the top surface of the battery pack. Furthermore, with this battery pack, the first seal portion can prevent water from entering through the through hole in the battery pack.

[0008] According to the present disclosure, it is possible to provide a battery pack in which bolts can be fastened to a vehicle body by passing through the case from the lower member of the case.

[0009] 3 is a diagram showing a vehicle undercarriage structure according to an embodiment of the present disclosure; a top view of a battery pack according to an embodiment of the present disclosure; a cross-sectional view of a battery pack mounting structure according to an embodiment of the present disclosure; an enlarged view of part A of FIG. 3; a perspective view showing an upper surface structure of a first member and a second member according to an embodiment of the present disclosure; a perspective view showing a lower surface structure of a first member and a second member according to an embodiment of the present disclosure; a perspective view showing a first reinforcing member and a second reinforcing member according to an embodiment of the present disclosure;

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following description and drawings, the right side relative to the direction of travel of a vehicle C will be referred to 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 the present disclosure is a structure for a battery pack P that is disposed on the underside D of a floor C1 of a vehicle C. The vehicle C of the present disclosure is a plug-in hybrid electric vehicle (PHEV) that can be externally charged or externally powered. The vehicle C has an exhaust pipe E2 through which exhaust from an internal combustion engine E1 passes. The battery pack P is composed of secondary batteries such as lithium-ion batteries, and a battery module made up of a plurality of battery cells is disposed inside.

[0012] As shown in Figures 1, 2, 3, and 4, the battery pack mounting structure 1 includes 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] The case 2 is a member for sealing the battery. As shown in FIG. 3 , the case 2 includes a housing member (an example of a lower member) 2a and a lid member (an example of an upper member) 2b that closes an opening 2c of the housing member 2a. The housing member 2a includes left and right side portions 22, a bottom portion 23 that connects the left and right side portions 22 to each other, a plurality of left and right support members 25a that extend in the left-right direction (the same as the width direction of the vehicle C or the vehicle width direction) and support the housing member 2a, and a plurality of front and rear support members 25b that extend in the front-rear direction and support the housing member 2a. Brackets 24 are fixed to the left and right side portions 22, respectively. The brackets 24 are fixed to side members C2 of the vehicle C with bolts. In this embodiment, the housing member 2a is a sheet metal member formed by press-forming a plate-shaped metal.

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

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

[0016] As shown in Figures 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 Figure 1, the lower through-hole 4 is provided in approximately the center in the left-right and front-rear directions. In this embodiment, the lower through-hole 4 has an elliptical shape that is long in the left-right direction of the battery pack P. As shown in Figure 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 cover 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 and left-right directions of the vehicle. As shown in FIG. 2 , the upper through-hole 6, like the lower through-hole 4, is provided at approximately the center of the battery pack P in the left-right and front-rear directions. In this 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 protrusion 26c of the cover member 2b.

[0018] The first member 8 is positioned approximately in the center of the battery pack P in the left-right and front-rear directions, aligned with the position of the lower through-hole 4. In this embodiment, the first member 8 is positioned 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 tubular member 30 that is inserted into the lower through-hole 4 and the upper through-hole 6. As shown in FIG. 5 , the tubular 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 this embodiment, the first member 8 is a metal member or a resin member.

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

[0020] As shown in Fig. 5, the first seal portion 32 is disposed around the tubular member 30. In this 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 to follow the shape of the lower through-hole 4. The first seal portion 32 seals the gap between the periphery of the lower through-hole 4 (see Fig. 4) in the lower surface 23b of the accommodating member 2a and the upper surface 31a of the flange 31. This prevents water from entering the interior of the battery pack P through the lower through-hole 4.

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

[0022] As shown in Fig. 5, a plurality of bolt through holes 35 are arranged around the periphery of the flange 31. In this embodiment, the flange 31 is substantially rectangular, and bolt through holes 35 are arranged at the four corners of the flange 31. As shown in Fig. 4, weld bolts (not shown) fixed to the lower surface 23b of the housing member 2a are inserted into the bolt through holes 35. Nuts 36 are coupled to the weld bolts and tighten the flange 31.

[0023] The second member 10 is positioned approximately in the center of the battery pack P in the front-rear and left-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 cover member 2b. The second member 10 is a member having a through-hole 40 (an example of a third through-hole) through which the tubular member 30 is inserted. As shown in FIG. 6 , the second member 10 has the through-hole 40, a flange 41, a second seal portion 42, a fourth seal 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-holes 40 penetrate from the upper surface 41a to the lower surface 41b of the flange 41. The number of through-holes 40 is formed to match the number of tubular members 30. In this embodiment, two through-holes 40 are formed side by side in the left-right direction. The through-holes 40 have a diameter slightly larger than the diameter of the tubular members 30. In this embodiment, the through-holes 40 are the inner peripheral surfaces of the tubular members extending from the upper surface 41a of the flange 41. As shown in FIG. 4 , an O-ring 34 comes into contact with this inner peripheral surface, thereby sealing the outer peripheral surface of the tubular members 30 and the inner peripheral surface of the through-holes 40. This prevents water from entering the interior of the battery pack P from the outer periphery of the tubular members 30.

[0025] As shown in FIG. 6 , the second seal 42 is disposed around the through-hole 40. In this embodiment, the second seal 42 is formed by attaching a seal member made of rubber or resin to a groove formed in the flange 41. As shown in FIG. 4 , the second seal 42 is formed to follow the shape of the upper through-hole 6. The second seal 42 seals between the periphery of the upper through-hole 6 on the upper surface 26 a of the cover member 2 b and the lower surface 41 b of the flange 41. In this way, the second seal 42, together with the O-ring 34, seals between the tubular member 30 and the upper through-hole 6. As a result, water is prevented from entering the interior of the battery pack P through the upper through-hole 6.

[0026] As shown in Fig. 6, the fourth seal 43 is formed around the lower surface 41b of the flange 41. The fourth seal 43 is a dust seal made of rubber or resin. As shown in Fig. 4, the fourth seal 43 seals 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 seal 42.

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

[0028] 3 and 4, the bolt 12 passes through the tubular member 30 and is fastened to a body member C3 of the vehicle C. The body member C3 is a structural member that is disposed between a pair of side members C2 and extends in the left-right direction. The body member C3 is, for example, a cross member.

[0029] As shown in FIG. 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 FIG. 1 , in this embodiment, three first reinforcing members 14 are arranged side by side in the front-rear direction. The lower through-hole 4 and the first member 8 are arranged at positions offset in the front-rear direction from the first reinforcing member 14 when viewed from the underside D. As shown in FIG. 7 , the first reinforcing member 14 has a rib 14a, a through-hole 14b, a pair of left and right flanges 14c (one example of both end portions) extending in the left-right direction, and a flange 14d extending along the tunnel section 3. The rib 14a is protruded toward the underside D of the tunnel section 3. The through-hole 14b penetrates the pair of left and right flanges 14c. In this embodiment, a total of four through-holes 14b are arranged, two on each side. The first reinforcing member 14 is a sheet metal member formed by press-molding a plate-shaped metal member.

[0030] 4, the first member 8 is disposed in the tunnel section 3. The lower ends 12a of the bolts 12 that are inserted through the tubular members 30 of the first member 8 are positioned above the lower ends 14e of the ribs 14a of the first reinforcing members 14. This makes it difficult for heat generated from the exhaust pipe E2 to reach the first member 8.

[0031] 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 into the through hole 14b of the first reinforcing member 14.

[0032] As shown in FIG. 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 disposed so as to be vertically overlapped with the first reinforcing member 14. As shown in FIG. 7 , the second reinforcing member 16 is a sheet metal member having a U-shaped cross section with an opening facing downward. 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 protrudes toward the lower side D. The through holes 14b are provided at the left and right ends of the second reinforcing member 16 and penetrate the second reinforcing member 16. In this embodiment, a total of four through holes 16b are provided, two at each of the left and right ends. The flange 16c is provided around the periphery of the second reinforcing member 16. The second reinforcing member 16 is fixed to the housing member 2a by inserting a weld bolt welded to the housing member 2a into the through hole 16b and tightening the weld bolt with a nut.

[0033] The weight of the battery is applied near the center of the housing member 2a of the battery pack P. For this reason, stress tends to concentrate near the center of the battery pack P. In particular, when the battery pack P has tunnel portions 3 in the left and right directions, stress concentration is even more likely to occur.

[0034] However, the battery pack mounting structure 1 allows the bolt 12 to pass through from the lower surface 23b to the upper surface 26a of the battery pack P. By fastening the bolt 12 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 bolt 12 from the underside D of the battery pack P. This makes the battery pack mounting structure 1 easy to work with.

[0035] Furthermore, according to this battery pack mounting structure 1, the first member 8 and the second member 10 can be used to seal the periphery of the lower through-hole 4 and the upper through-hole 6 of the battery pack P. This allows the battery pack P to be kept sealed.

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

[0037] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the multiple modifications described in this specification can be combined as needed.

[0038] (a) In the above embodiment, the battery pack P has been described as having a tunnel portion 3, but the present disclosure is not limited to this. The battery pack P may be a battery pack that does not have a tunnel portion 3.

[0039] (b) In the above embodiment, two bolts 12 arranged side by side in the left-right direction are fastened to the vehicle body member C3. However, the present disclosure is not limited to this. 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 are disposed in the approximate center of the battery pack P in the left-right and front-rear directions, and the bolt 12 is fixed thereto. However, the present disclosure is not limited to this. The position of the bolt 12 may be appropriately determined in accordance with the load applied to the battery pack P.

[0041] 1: Mounting structure, 2: Case, 2a: Housing member, 2b: Cover member 3: Tunnel portion 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 portion, 33: Third seal portion 34: O-ring 40: Through-hole, 41: Flange, 42: Second seal portion, 43: Fourth seal portion C: Vehicle, C1: Floor, C3: Vehicle body member P: Battery pack

Claims

1. A mounting structure for a battery pack fixed to an underside of a vehicle floor, comprising: A case for housing a battery; A first through hole provided in a 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 into 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 that is inserted through the cylindrical member and fastened to a body of the vehicle; Equipped with The first member is a flange disposed on the lower member side of the case and to which the tubular member is connected; a first seal portion disposed around the tubular member and sealing between the periphery of the first through hole and the flange; having The second member has a second seal portion that seals between the second through hole and the cylindrical member. Battery pack mounting structure.

2. A mounting structure for a battery pack fixed to an underside of a vehicle floor, comprising: A case for housing a battery; A first through hole provided in a 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 into 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 that is inserted through the cylindrical member and fastened to a body of the vehicle; Equipped with The first member is a flange disposed on the lower member side of the case and to which the tubular member is connected; a first seal portion disposed around the tubular member and sealing between the periphery of the first through hole and the flange; having The first member is disposed at a position where stress is concentrated due to the weight of the battery pack. Battery pack mounting structure.

3. The position where the stress is concentrated is the center in the width direction of the vehicle. The battery pack mounting structure according to claim 2 .

4. The position where the stress is concentrated is the center in the front-rear direction of the vehicle. The battery pack mounting structure according to claim 2 .

5. A mounting structure for a battery pack fixed to an underside of a vehicle floor, comprising: A case for housing a battery; A first through hole provided in a 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 into 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 that is inserted through the cylindrical member and fastened to a body of the vehicle; Equipped with The first member is a flange disposed on the lower member side of the case and to which the tubular member is connected; a first seal portion disposed around the tubular member and sealing between the periphery of the first through hole and the flange; a third seal portion around the flange for sealing between the lower member of the case and the flange; having Battery pack mounting structure.

6. the case extends in a front-rear direction of the vehicle, and the lower member has a tunnel portion that bulges in an arch shape toward an upper portion of the vehicle, Further, a reinforcing member is provided in the tunnel portion to reinforce the tunnel portion. The first member is disposed in the tunnel portion, The lower end of the bolt is located above the lower end of the reinforcing member. The battery pack mounting structure according to any one of claims 1 to 5.