Battery pack

Abstract

To provide a battery pack capable of improving waterproofing.SOLUTION: A battery pack includes a battery case having a first flange portion at an upper portion, a battery module housed in the battery case, a base member fixed to the first flange portion via a fastening portion, a device case having a second flange portion fixed to the first flange portion and the base member via the fastening portion, with the ends of the second flange portion and the first flange portion arranged side by side one above the other, an electronic device housed in the device case, and a sealing member interposed between the first flange portion and the second flange portion, arranged to surround the periphery of the device case and positioned outside the fastening portion in the inward / outward direction of the device case.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery pack. [Background technology]

[0002] For example, Patent Document 1 discloses a battery pack to be mounted on a vehicle or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-165836 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery pack described above, it is conceivable to mount a device case (junction box) housing an electronic device on top of a battery case housing a battery module. This configuration reduces the overall height of the battery pack and also facilitates connection between the electronic device and the battery. However, in this configuration, the fastening portion between the device case and the battery case or the base member is located above the battery case, which raises concerns about waterproofing of the device case and the battery case.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a battery pack that can improve waterproofing. [Means for solving the problem]

[0006] A battery pack according to one embodiment of the present invention comprises: a battery case having a first flange portion at an upper portion; a battery module housed in the battery case; a base member fixed to the first flange portion via a fastening portion; an equipment case having a second flange portion fixed to the first flange portion and the base member via the fastening portion, with the ends of the second flange portion and the first flange portion arranged side by side vertically; an electronic device housed in the equipment case; and a sealing member interposed between the first flange portion and the second flange portion, arranged to surround the periphery of the equipment case and positioned outside the fastening portion in the inward / outward direction of the equipment case. [Effects of the Invention]

[0007] According to the above aspect of the present invention, waterproofing can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional side view of a battery pack according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view of the battery pack shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A battery pack according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiment.

[0010] Fig. 1 is a schematic side cross-sectional view of a battery pack 10 according to one embodiment of the present invention. Fig. 2 is a schematic plan view of the battery pack 10 shown in Fig. 1. The battery pack 10 of this embodiment can be mounted and used in vehicles such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). The battery pack 10 can be disposed, for example, below a floor panel and fixed to a cross member or reinforcement, which is a structural member of the vehicle.

[0011] When the battery pack 10 is mounted on a vehicle, for example, arrow X in the drawing indicates the width direction of the vehicle, arrow Y indicates the front-rear direction of the vehicle, arrow Z1 indicates the upward direction of the vehicle, and arrow Z2 indicates the downward direction of the vehicle. For convenience of explanation, the inside of the box-shaped battery case 12 and device case 18 are referred to as the inside (inner side), and the outside of the case is referred to as the outside (outer side). These designations of directions indicate one example of mounting the battery pack 10 on a vehicle, and the mounting direction of the battery pack 10 on a vehicle, etc. is not limited to this.

[0012] 1 and 2, the battery pack 10 includes a battery case 12, a battery module 14, a base member 16, an equipment case 18, and an electronic device 20. The battery pack 10 is configured such that the equipment case 18, which houses the electronic device 20 including an ECU, is attached to the battery case 12, which houses the battery module 14.

[0013] The battery case 12 has a lower case 22 and an upper case 23. The battery case 12 is a box-shaped housing that houses the battery module 14.

[0014] The lower case 22 has a bottom plate 22a, a side wall 22b, and a joint 22c. The bottom plate 22a is a plate that is disposed substantially horizontally along, for example, the XY plane. The side wall 22b is a standing wall that rises upward from the edge of the bottom plate 22a. The side wall 22b may gradually slope upward toward the outside of the battery case 12. The side wall 22b extends along the periphery of the bottom plate 22a, forming a ring shape as a whole. The joint 22c is located at the top of the lower case 22. The joint 22c is a flange-like portion formed by bending the upper end of the side wall 22b toward the outside of the battery case 12.

[0015] The upper case 23 has a joint 23a, a side wall 23b, a top panel 23c, and a flange (first flange) 23d. The joint 23a is located at the bottom of the upper case 23. The joint 23a is a flange-shaped portion formed by bending the lower end of the side wall 22b toward the outside of the battery case 12. The side wall 23b is a standing wall that rises upward from the inner end of the joint 23a. The side wall 23b may be gradually inclined in a stepped manner toward the inside of the battery case 12 as it extends upward. The joint 23a and the side wall 23b extend in an annular shape so as to face the joint 22c and side wall 22b of the lower case 22.

[0016] As shown in the plan view of Fig. 2, the device case 18 has a smaller outer shape than the battery case 12. The device case 18 can be attached to the battery case 12 at a position closer to one side (e.g., the front of the vehicle) in the front-to-rear direction (Y direction). The top plate portion 23c is a plate that covers the portion of the upper surface of the battery case 12 that is not covered by the device case 18. For this reason, in the configuration example shown in Fig. 2, the top plate portion 23c is formed, for example, in a substantially U-shape.

[0017] The flange portion 23d functions as a mounting portion of the device case 18. The flange portion 23d has an annular shape that borders the periphery of the device case 18. Therefore, the outer shape of the flange portion 23d is smaller than the outer shapes of the joint portion 23a and the side wall 23b. The device case 18 and the battery case 12 have their edges positioned substantially in the Y direction at one side located on the front side of the vehicle, for example. At this one side (the left edge in FIG. 1 ), the flange portion 23d has a shape in which the upper end of the side wall 23b is bent toward the inside of the battery case 12. At the other three sides where the edges of the device case 18 and the battery case 12 do not match, the flange portion 23d has a shape in which the edge of the top plate portion 23c is cranked up one step and extended toward the inside of the battery case 12.

[0018] The joint portion 22c of the lower case 22 and the joint portion 23a of the upper case 23 are fixed by joining or fastening. This gives the battery case 12 a box-like shape with an opening (top opening 23e) on part of the top surface (inside the flange portion 23d). A seal member 26 is interposed between the joint portions 22c and 23a. The seal member 26 may be, for example, a liquid sealant that has been applied and cured. The seal member 26 is provided in an annular shape over the entire length of the joint portions 22c and 23a. The lower case 22 and the upper case 23 may be integrally molded.

[0019] The battery module 14 is, for example, a module in which a plurality of battery cells are stacked. The battery modules 14 are placed on the upper surface side of the bottom plate 22a inside the battery case 12, and, for example, three battery modules 14 are arranged in the front-rear direction.

[0020] A cross member 28 extending along the width direction of the battery case 12 is installed on the side of each battery module 14. The cross member 28 is fixed to the upper surface of the bottom plate 22a by bonding or fastening, and protrudes upward to near the upper end of the lower case 22. Studs 28a are fixed to the upper end surface of the cross member 28 at various locations along its length (vehicle width direction). An upward-opening female screw hole is formed in the center of the studs 28a.

[0021] The base member 16 is installed so as to close the top opening 23e of the upper case 23, which is surrounded by the flange portion 23d. The base member 16 is a plate for placing the electronic device 20 on the battery case 12. The bottom surface of the base member 16 is fixed to the top end surfaces of the studs 28a with bolts 29. The peripheral portion of the base member 16 is fastened to the battery case 12 and the device case 18 using fastening portions 30, which will be described later. This allows the base member 16 to be supported stably and approximately horizontally on the battery case 12.

[0022] The device case 18 houses the electronic device 20, which is composed of an ECU and the like, and serves as a junction box that aggregates the wiring of the battery pack 10. The device case 18 is attached to the top of the battery case 12. The device case 18 of this embodiment is provided so as to surround the peripheral side surfaces of the electronic device 20, and the opening at the top (top opening 18d) is closed by a cover member 32.

[0023] The device case 18 has a side wall 18a, a flange portion (second flange portion) 18b, and a cover attachment portion 18c.

[0024] The side wall 18a is a standing wall that forms the outer peripheral side surface of the equipment case 18. The side wall 18a can be inclined from the inside to the outside of the equipment case 18 from bottom to top. This gives the equipment case 18 a tapered shape in which the surface area of ​​the top surface (top opening 18d) is larger than that of the bottom surface closed by the base member 16. The side wall 18a extends along the periphery of the base member 16, thereby forming a ring shape as a whole.

[0025] The flange portion 18b functions as an attachment portion for the battery case 12. The flange portion 18b is a portion where the lower end of the side wall 18a is bent toward the inside of the device case 18. The flange portion 18b has an annular shape that frames the periphery of the base member 16. The flange portion 18b is disposed opposite the flange portion 23d of the upper case 23, and they are fastened to each other by fastening portions 30.

[0026] The fastening portions 30 are provided at various locations on the flange portions 18b, 23d. The fastening portions 30 are disposed closer to the tip than the center in the direction in which the flange portions 18b, 23d protrude from the side walls 18a, 23b, etc. In other words, the fastening portions 30 are disposed inward in the inward / outward direction of the device case 18 and the upper case 23 relative to the center in the direction in which the flange portions 18b, 23d protrude.

[0027] The fastening portion 30 is composed of, for example, a bolt 30a, a nut 30b, and a washer 30c. The bolt 30a can be installed so as to penetrate the flange portions 18b and 23d from bottom to top. In this embodiment, the base member 16 is stacked below the flange portion 23d of the upper case 23. The bolt 30a penetrates the base member 16, the flange portion 23d, and the flange portion 18b, in that order, from bottom to top. A nut 30b is threaded onto the tip of the bolt 30a via a washer 30c. This allows the fastening portion 30 to integrally fasten the device case 18, the battery case 12, and the base member 16.

[0028] In this case, the outer end 18b1 of the flange portion 18b is arranged vertically alongside the outer end 23d1 of the flange portion 23d. In other words, the end 18b1 of the flange portion 18b on the side wall 18a side and the end 23d1 of the flange portion 23d on the side wall 23b and top plate portion 23c side are vertically aligned in the inside-outside direction of the device case 18 and the battery case 12. As a result, in the battery pack 10, the bending ridgelines of the flange portions 18b and 23d coincide with each other, and the outer surfaces of the connection portions of the device case 18 and the battery case 12 are formed to be approximately flush.

[0029] A seal member 34 is interposed between the flange portions 18b, 23d. The seal member 34 may be, for example, a liquid urethane sealant that has been applied and cured. The seal member 34 is annularly provided over the entire length of the flange portions 18b, 23d. The seal member 34 is disposed outside the fastening portion 30 in the inward / outward direction of the device case 18 and the battery case 12. In other words, the seal member 34 is disposed between the fastening portion 30 and the end portion 18b1. As a result, the outside of the fastening portion 30 of the battery pack 10 of this embodiment is sealed with the annular seal member 34.

[0030] The cover mounting portion 18c functions as a mounting receiving portion for the cover member 32. The cover mounting portion 18c is a portion where the upper end of the side wall 18a is bent toward the outside of the equipment case 18. The cover mounting portion 18c has an annular shape that extends along the periphery of the equipment case 18. The edge of the cover member 32 is placed on the upper surface of the cover mounting portion 18c, and the cover member 32 is fastened to the cover mounting portion 18c with bolts 36. In this way, the cover member 32 closes the top opening 18d of the equipment case 18.

[0031] A gasket 38 is interposed between the cover member 32 and the cover mounting portion 18c. The gasket 38 is provided in an annular shape over the entire length of the cover mounting portion 18c. The gasket 38 has a through hole in the thickness direction at the portion where the bolt 36 is installed, and the bolt 36 is inserted into this through hole.

[0032] In this way, the lower part of the device case 18 is waterproofed against the battery case 12 by the sealing member 34, and the upper part is waterproofed against the cover member 32 by the gasket 38. This allows the device case 18 to seal the electronic device 20 inside. Maintenance work on the electronic device 20 can be easily performed by removing the cover member 32 of the battery pack 10. The device case 18 and the cover member 32 may be molded as a single unit.

[0033] As described above, the battery pack 10 of this embodiment includes the battery case 12 having the flange portion 23d on the top, the battery module 14 housed in the battery case 12, the base member 16 fixed to the flange portion 23d via the fastening portion 30, the device case 18 having the flange portion 18b fixed to the flange portion 23d and the base member 16 via the fastening portion 30 and arranged with the ends of the flange portions 18b and 23d aligned vertically, and the electronic device 20 housed in the device case 18. The battery pack 10 further includes a seal member 34 interposed between the flange portions 18b and 23d, provided so as to surround the periphery of the device case 18, and disposed outside the fastening portion 30 in the inside-outside direction of the device case 18.

[0034] Therefore, in the battery pack 10, by placing the device case 18 on top of the battery case 12, the overall height can be reduced and the connection between the electronic device 20 and the battery module 14 can be facilitated. At this time, the outside of the fastening portion 30 between the device case 18 and the battery case 12 of the battery pack 10 is sealed with a seal member 34 around the entire periphery. This prevents water from seeping into the device case 18 or the battery case 12 through the fastening portion 30, improving the waterproofness of the battery pack 10.

[0035] In addition, in the battery pack 10, the ends of the flanges 18b, 23d of the device case 18 and the battery case 12, which sandwich the sealing member 34, are arranged vertically side by side. This allows the bending ridges of the flanges 18b, 23d to match, improving the bending rigidity of the sealing surfaces that press the sealing member 34. As a result, the battery pack 10 can ensure the compression pressure of the sealing member 34 on the flanges 18b, 23d, further improving the waterproofness of the sealing member 34. In this case, the application line of the sealing member 34 can be set above the base member 16. This further improves the compression pressure of the sealing member 34 on the flanges 18b, 23d, further improving the waterproofness. Furthermore, because the bending ridges of the flanges 18b, 23d match, it is possible to reduce the intrusion and adhesion of water from the outside to the area where the sealing member 34 is installed between the flanges 18b, 23d, thereby further improving the waterproofness.

[0036] The present invention is not limited to the above-described embodiment, and can of course be freely modified within the scope of the gist of the present invention. [Explanation of symbols]

[0037] 10 Battery pack 12 Battery case 14 Battery Module 16 Base member 18 Equipment Case 18b, 23d flange 20 Electronic equipment 26,34 Sealing member 30 Fastening part 32 Cover member

Claims

[Claim 1] a battery case having a first flange portion at an upper portion; a battery module housed in the battery case; a base member fixed to the first flange portion via a fastening portion; an equipment case including a second flange portion fixed to the first flange portion and the base member via the fastening portion, and in which ends of the second flange portion and the first flange portion are arranged vertically side by side; an electronic device housed in the device case; a seal member interposed between the first flange portion and the second flange portion, provided to surround the periphery of the device case, and disposed outside the fastening portion in an inward / outward direction of the device case; A battery pack comprising:

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