Vehicle battery pack

Abstract

In order to prevent water from entering the interior through a joint of a seal member, a vehicle battery pack (1) has: a lower case (1B); an upper case (1A) that covers an opening of the lower case, and is fastened to the lower case at the outer peripheral part of the lower case and a cross member (14); and a coating-type seal member (13) that is disposed along the entire periphery of the outer peripheral part of the lower case, and seals a portion between the lower case and the upper case. Joints (S) of the seal member are provided on the outer peripheral part (M1, M2) on and at the inner side of lines of triangles (T), in a plan view of a vehicle, each defined by a fastening part (17) that fastens the cross member and the upper case, and two fastening parts (16, 16) that sandwich an extension line (L1) along the center of the cross member, among fastening parts (16) that fasten the outer peripheral part and the upper case.

Description

Vehicle battery pack 【0001】 The present invention relates to a battery pack that houses a plurality of battery modules and is mounted under the floor of a vehicle or the like. 【0002】 A battery pack for an electric vehicle is known that has a tray on which batteries are placed at the bottom, a cover that covers the upper part of the tray, and a sealing member that is arranged along the entire circumference of the upper end of the side wall of the tray and is sandwiched between the tray and the cover to seal between the tray and the cover (see Patent Document 1). In this battery pack, a water receiving part that partitions from the part where the battery is placed is provided in contact with the side wall, and a joint of the sealing member is arranged at the upper end part of the side wall in contact with the water receiving part. 【0003】 Japanese Patent Application Laid-Open No. 2013-65419 【0004】 However, since the battery pack of the above prior art has a structure premised on water entering the tray from the joint of the sealing member, a structure that can prevent water from entering the tray from the joint of the sealing member is desired. 【0005】 The problem to be solved by the present invention is to provide a vehicle battery pack that can prevent water from entering inside from the joint of the sealing member. 【0006】 According to the present invention, the problem is solved by providing the joint of the coating type sealing member arranged along the entire circumference of the outer peripheral part of the lower case on the line and inside of the triangle in the plan view of the vehicle, which is defined by two fastening parts sandwiching the extension line of the center of the cross member among the fastening part between the cross member and the upper case and the fastening part between the outer peripheral part and the upper case. 【0007】 According to the present invention, it is possible to prevent water from entering the lower case from the joint of the sealing member. 【0008】This is a plan view showing a battery pack according to one embodiment of the present invention (with the upper case removed). This is a perspective view showing the battery pack according to one embodiment of the present invention mounted under the floor of an automobile body. This is a cross-sectional view along line III-III in Figure 1 (including the upper case and automobile body). This is an enlarged cross-sectional view of part IV in Figure 3. This is a cross-sectional view for illustrating a coating-type sealing member according to the present invention. This is a plan view for illustrating a coating-type sealing member according to an embodiment of the present invention. This is a cross-sectional view for illustrating a coating-type sealing member according to an embodiment of the present invention. This is an enlarged plan view of part VII in Figure 1. 【0009】 Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a plan view showing a battery pack 1 according to an embodiment of the present invention (with the upper case 1A removed), Figure 2 is a perspective view showing the battery pack 1 of this embodiment mounted under the floor of the automobile body 2, and Figure 3 is a cross-sectional view along the line III-III in Figure 1 (including the upper case 1A and the automobile body 2). 【0010】 The vehicle battery pack 1 of this embodiment is a type of housing that is mounted under the floor of the automobile body 2 and houses and supports a battery 3 inside. As shown in Figures 1 to 3, the battery pack 1 comprises an upper case 1A and a lower case 1B. The upper case 1A is made of, for example, a plate-shaped steel material. The lower case 1B includes, for example, a plate-shaped or block-shaped bottom frame 11 and a plurality of block-shaped or plate-shaped side frames 12 fixed to the outer periphery of the bottom frame 11. 【0011】The bottom frame 11 in this embodiment may be constructed as a single integrated part formed by extrusion molding of aluminum material, or alternatively, it may be divided into several sub-bottom frames along dividing lines along the front-rear direction of the automobile body 2, and the divided sub-bottom frames may be welded together to assemble a single flat plate. Alternatively, one or more bottom frames 11 may be joined to one or more bottom frames 11 to form a space for circulating refrigerant, and the bottom frame 11 may be reinforced with multiple members extending in the front-rear direction of the automobile body 2. Although not shown in the figures, in the bottom frame 11 of this embodiment, the refrigerant cooled by a refrigerant cooling device such as a chiller can be circulated through the space formed in the bottom frame 11, thereby cooling the battery 3 that is in contact with and mounted on the bottom frame 11. 【0012】 The side frame 12 of this embodiment is composed of a pair of left and right side frames 12a extending in the front-rear direction of the vehicle, a front frame 12b extending in the vehicle width direction at the front end of the side frame 12a, and a rear frame 12c extending in the vehicle width direction at the rear end of the side frame 12a. These bottom frame 11 and side frames 12 are not particularly limited, but can be made of extruded aluminum. If they are made of extruded aluminum, they will have excellent heat transfer properties, weight reduction, and noise shielding properties. 【0013】 The battery pack 1 shown in Figure 1 is assembled as a roughly rectangular parallelepiped housing by fixing the side frames 12 to the outer circumference of a plate-shaped or block-shaped bottom frame 11 using a sealing adhesive or welding, and closing the opening on the top surface of the lower case 1B with the upper case 1A via a sealing member 13. The battery 3 is then housed in a fixed state within the space enclosed by the bottom frame 11, the upper case 1A facing it, and the four side frames 12. 【0014】The battery 3 (also called a battery pack) includes multiple battery modules 31, each of which is housed in a rectangular module case. A plan view of the battery 3 with the battery removed is shown in the lower left of Figure 1. Although not shown in the illustration, multiple thin batteries (also called single cells) are stored inside the module case in a stacked state. In this embodiment, the multiple battery modules 31 are arranged and fixed side by side on the surface of the bottom frame 11 such that the main surface of each of the multiple battery modules 31 is perpendicular to the surface of the bottom frame 11. An example of the arrangement of the battery 3 is shown by a dashed line in Figure 1. 【0015】 Reference numeral 14 in Figure 1 indicates a cross member fixed to the upper surface of the bottom frame 11 by welding or the like. This member reinforces the bottom frame 11 and also serves to secure the battery 3 by partitioning it. In this embodiment, the cross member 14 is provided in the central part of the vehicle in the longitudinal direction, extending in the vehicle width direction, and is bolted to the upper case 1A at the fastening portion on the upper surface of the cross member 14. 【0016】 As shown in Figures 2 and 3, the battery pack 1, with the battery 3 housed in this manner, is attached to the underside 21 of the automobile body 2 using a plurality of brackets 15 after the upper case 1A closes the upper opening of the lower case 1B. Specifically, the left and right sides of the battery pack 1 are attached to the sill inner panel 251 (or sill outer panel 252) of the sill 25, as shown in Figure 3, and the front and rear ends are attached directly or indirectly to the front floor panel 23 or rear floor panel 24, as shown in Figure 2. The underside of the automobile body 2 on which the battery pack 1 of this embodiment is mounted refers to the space outside the passenger compartment between the floor panels of the automobile body 2 (front floor panel 23 and rear floor panel 24) and the road surface (ground). 【0017】 In this way, as shown in Figure 2, the battery pack 1 of this embodiment is mounted over almost the entire area of ​​the underside of the automobile body 2, from the front of the front floor panel 23 to the front of the rear floor panel 24. In Figure 2, reference numeral 22 denotes the dashboard panel. 【0018】 In this embodiment, the battery pack 1 is assembled as a roughly rectangular prism-shaped housing by fixing four side frames 12 to the outer circumference of the bottom frame 11 using adhesive or welding to form the lower case 1B, and then closing the opening on the top with the upper case 1A. The battery pack 1 in this embodiment is also a watertight space with waterproof properties ensured. However, in order to perform maintenance, inspection, and replacement work on the battery 3, the upper case 1A must be detachable from the lower case 1B. 【0019】 Therefore, in the battery pack 1 of this embodiment, the upper case 1A is made detachable by fastening the upper case 1A to the lower case 1B with bolts or the like at the upper surface of the cross member 14 fixed to the bottom frame 11 and the upper surfaces of the four side frames 12 corresponding to the outer periphery of the lower case 1B. Reference numeral 16 in Figures 1 and 3 indicates bolt fastening points (66 in this example) between the upper case 1A and the upper surfaces of the four side frames 12, and reference numeral 17 in Figures 1 and 3 indicates bolt fastening points (4 in this example) between the upper case 1A and the upper surface of the cross member 14. 【0020】 Furthermore, in order to prevent water from entering the inside of the battery pack 1 from the outside through the gap between the upper case 1A and the lower case 1B, sealing members 13 are placed along the entire circumference of the upper surface of the four side frames 12 corresponding to the outer periphery of the lower case 1B, and the structure is such that the sealing members 13 are sandwiched between the upper surface of the side frames 12 and the upper case 1A. 【0021】 Figure 4 is an enlarged cross-sectional view of part IV in Figure 3, Figure 5 is a cross-sectional view illustrating a coating-type sealing member according to the present invention, and Figure 6B is a cross-sectional view illustrating a coating-type sealing member according to an embodiment of the present invention. 【0022】In this embodiment, the sealing member 13 is not a pre-molded product, but rather a coating-type sealing member. A coating-type sealing member is a type of sealing member in which an uncured two-component curing resin is applied to one or both of the joint surfaces of the upper case 1A and the lower case 1B, and then cured. It is also called a field-applied foamed gasket and is not particularly limited, but examples include a two-component curing polyurethane foam in which component A is a polyol and component B is diphenylmethane diisocyanate (MDI). 【0023】 In this embodiment, as shown in Figure 5, the sealing member 13 is applied by moving a robot hand (not shown) gripping the application nozzle 4 along one of the joint surfaces of the upper case 1A and the lower case 1B. In this embodiment, the sealing member 13, made of uncured two-component curable polyurethane foam or the like, is applied along the entire circumference of the upper surface of the side frame 12, which is the outer circumference of the lower case 1B, while moving the application nozzle 4. Here, in the application-type sealing member 13, as shown in Figure 5, application starts from the application start point P1, and after applying the entire circumference of the outer circumference of the lower case 1B, the application ends at the application end point P2, so a seam S is created where the application start point P1 and the application end point P2 overlap along the application direction. 【0024】 In this embodiment, the seams S include, as shown in the upper diagram of Figure 6B, a seam S in which a sealing member 13 near the coating end point P2 overlaps a sealing member 13 near the coating start point P1, and as shown in the lower diagram of Figure 6B, a seam S in which a sealing member 13 near the coating end point P2 overlaps side by side with a sealing member 13 near the coating start point P1. Such seams S may peel off in the opposite direction to the coating direction starting from the coating end point P2, and there is a risk that water may enter the inside of the battery pack 1 from the outside through these seams S. 【0025】Therefore, the joint S of the sealing member 13 in this embodiment is provided on the line of triangle T and on the inner outer periphery in a plan view of the vehicle, defined by the fastening portion 17 between the cross member 14 and the upper case 1A, and two fastening portions 16, 16 between the outer periphery of the lower case 1B and the upper case 1A that sandwich the extension line L1 of the center of the cross member 14. The configuration of the sealing member 13 and the installation configuration of the joint S in this embodiment will be described below. Figure 6A is a plan view illustrating a coating-type sealing member according to an embodiment of the present invention, and Figure 7 is an enlarged plan view of part VII in Figure 1. 【0026】 As shown in Figure 6A, the sealing member 13 of this embodiment consists of two sealing members 13, 13 arranged parallel to the outer periphery of the lower case 1B, that is, the upper surface of the side frame 12. In other words, the sealing member 13 of this embodiment includes a sealing member 13 arranged around the entire inner circumference of the outer periphery of the lower case 1B, and a sealing member 13 arranged parallel to it around the entire outer circumference of the outer periphery of the lower case 1B, and is arranged to bypass the fastening portion 16 between the upper case 1A and the lower case 1B. Note that the sealing member according to the present invention may include one or three or more sealing members 13. When composed of one sealing member 13, it may be arranged inside or outside the fastening portion 16 between the upper case 1A and the lower case 1B, but it is desirable that the joint S be arranged inside the fastening portion 16. 【0027】 As shown in Figure 7, the joint S of the sealing member 13 is defined by the fastening portion 17 between the cross member 14 and the upper case 1A, and two fastening portions 16, 16 between the outer circumference of the lower case 1B and the upper case 1A that sandwich the extension line L1 of the center of the cross member 14. In a plan view of the vehicle, it is located on the line of triangle T and on the inner outer circumference M1 or M2. Here, although there are two fastening portions 17 between the cross member 14 and the upper case 1A in the embodiment shown in Figure 7, either one is acceptable. Also, although there are four combinations of the two fastening portions 16, 16 that sandwich the extension line L1 of the center of the cross member 14 in the embodiment shown in Figure 7, any combination is acceptable. 【0028】Furthermore, in the embodiment shown in Figure 7, there are eight triangles (in a plan view of the vehicle) formed by one fastening portion 17 and two fastening portions 16, 16, but any of these triangles can be used. In Figure 7, the triangle with the smallest area is shown with a solid line, and the triangle with the largest area is shown with a dashed line. In this embodiment, the seam S of the seal member 13 is located at least on the outer periphery indicated by reference numeral M2, preferably on the outer periphery indicated by reference numeral M1. Alternatively, it may be located on the outer periphery M3 of the lower case 1B on the extension of the cross member 14 shown by the dashed line in Figure 7. Since the lines and inside of the triangles shown with solid or dashed lines are tightly fastened by one fastening portion 17 and two fastening portions 16, 16, peeling of the seam S of the seal member 13 can be reliably prevented. 【0029】 As shown in Figure 6A, if the sealing member 13 includes two sealing members 13, 13, the joint S of one sealing member 13 may be provided on the outer circumference of the lower case 1B on one end side of the cross member 14 (for example, the left side of the vehicle), and the joint S of the other sealing member 13 may be provided on the outer circumference of the lower case 1B on the other end side of the cross member 14 (for example, the right side of the vehicle). Alternatively, if the sealing member 13 includes two sealing members 13, 13, the joints S, S of the two sealing members 13, 13 may be provided on the outer circumference of the lower case 1B on either the left end side of the cross member (for example, the left side of the vehicle) or the other end side (for example, the right side of the vehicle). 【0030】 Furthermore, the joint S of the sealing member 13 in this embodiment is preferably located on the line and inside of the triangle described above, and is provided on the outer circumference M4 of the lower case 1B, which corresponds to the area between the front and rear ends of the sill 25 of the vehicle along the longitudinal direction of the vehicle, as shown in Figure 2. 【0031】 Furthermore, it is preferable that the joint S of the sealing member 13 in this embodiment be provided on the outer circumference of the lower case 1B at a height H2 above the height H1 of the fastening portion between the vehicle sill 25 and the lower case 1B in the vertical direction of the vehicle. 【0032】Furthermore, as shown in Figure 6B, the sealing member 13 of this embodiment may be positioned such that the coating endpoint P2 is located behind the coating start point P1 in the front-rear direction of the vehicle, or alternatively, the coating endpoint P2 may be positioned in front of the coating start point P1 in the front-rear direction of the vehicle. 【0033】 As described above, the battery pack 1 of this embodiment has a lower case 1B with an opening at the top, a cross member 14 extending in the vehicle width direction and on which the battery 3 is mounted at the bottom, an upper case 1A that covers the opening of the lower case 1B and is fastened to the lower case 1B at the outer circumference of the lower case 1B and the cross member 14, and a part arranged along the entire circumference of the outer circumference of the lower case 1B and sandwiched between the outer circumference and the upper case 1A. In a vehicle battery pack 1 having a coating-type sealing member 13 that seals the space between the upper case 1A and the vehicle, the seam S of the sealing member 13 is provided on the line of a triangle T in a plan view of the vehicle and on the inner outer peripheral M1, M2, defined by the fastening portion 17 between the cross member 14 and the upper case 1A, and two fastening portions 16, 16 of the outer peripheral portion that sandwich the extension line L1 of the center of the cross member 14. In other words, since the seam S of the sealing member 13 is provided in the area where the fastening force between the upper case 1A and the lower case 1B is greatest, peeling of the seam S is prevented, and water can be prevented from entering the inside of the battery pack 1 from the seam S. 【0034】 Furthermore, according to the battery pack 1 of this embodiment, since the sealing member 13 consists of two sealing members 13, 13 arranged in parallel, even if the sealing performance of one sealing member 13 deteriorates, the sealing performance can be ensured by the other sealing member 13, thereby increasing the robustness of the watertight performance. 【0035】Furthermore, according to the battery pack 1 of this embodiment, the joint S of one of the two sealing members 13, 13 is provided on the outer circumference of one end of the cross member 14, and the joint S of the other sealing member 13 is provided on the outer circumference of the other end of the cross member 14. Therefore, even if the sealing performance of the joint S of one sealing member 13 deteriorates, the sealing performance can be ensured by the other sealing member 13, thereby increasing the robustness of the watertight performance. 【0036】 Furthermore, according to the battery pack 1 of this embodiment, the joints S, S of the two sealing members 13, 13 are provided on the outer circumference of one end or the other end of the cross member 14, which increases the operational efficiency of the coating robot when applying the coating-type sealing member 13 and shortens the coating time. In addition, by concentrating the joints S of the sealing member 13 in one place, the objects to be protected are concentrated, and the protective structure can be simplified and made easier to implement. 【0037】 Furthermore, according to the battery pack 1 of this embodiment, the seam S of the sealing member 13 is provided on the outer peripheral portion M3 on the extension line of the cross member 14, so that the seam S of the sealing member 13 is provided in the area where the fastening force between the upper case 1A and the lower case 1B is greatest. As a result, peeling of the seam S is prevented, and water can be prevented from entering the inside of the battery pack 1 through the seam S. 【0038】 Furthermore, according to the battery pack 1 of this embodiment, the seam S of the sealing member 13 is provided on the outer circumference M4, which corresponds to the area between the front and rear ends of the sill of the vehicle along the longitudinal direction of the vehicle. As a result, the seam S is hidden by the sill 25, and water hammer such as splashes when the vehicle is running can be prevented from directly hitting the seam S. 【0039】Furthermore, according to the battery pack 1 of this embodiment, the seam S of the sealing member 13 is located on the outer circumference above the fastening portion between the vehicle's sill 25 and the lower case 1B in the vertical direction of the vehicle. Therefore, the seam S is hidden by the sill 25 and the lower case 1B, preventing water hammer such as splashes when the vehicle is running from directly hitting the seam S. 【0040】 Furthermore, according to the battery pack 1 of this embodiment, the coating-type sealing member 13 includes a joint S where the coating start point P1 and the coating end point P2 overlap along the coating direction, with coating starting from the coating start point P1 and ending at the coating end point P2. Since the coating end point P2 is located behind the coating start point P1 in the front-rear direction of the vehicle, when the vehicle is moving forward, water hammer kicked up from the front wheels of the vehicle is prevented from directly hitting the coating end point P2 of the joint S. As a result, the joint S is prevented from peeling off, and water can be prevented from entering through the joint S. 【0041】 Furthermore, according to the battery pack 1 of this embodiment, the coating-type sealing member 13 includes a joint S where the coating start point P1 and the coating end point P2 overlap along the coating direction, with coating starting from the coating start point P1 and ending at the coating end point P2. Since the coating end point P2 is located in front of the coating start point P1 in the front-rear direction of the vehicle, when the vehicle is moving in reverse, water hammer kicked up from the rear wheels of the vehicle is prevented from directly hitting the coating end point P2 of the joint S. As a result, the joint S is prevented from peeling off, and water can be prevented from entering through the joint S. 【0042】 Furthermore, since the battery pack 1 of this embodiment is mounted under the floor of the vehicle, it is possible to prevent water from entering the inside of the battery pack 1 through the seams S, even in the event of water hammer such as splashes when the vehicle is in motion. 【0043】1...Battery pack 1A...Upper case 1B...Lower case 11...Bottom frame 12...Side frame 12a...Side frame 12b...Front frame 12c...Rear frame 13...Sealing member 14...Cross member 15...Bracket 16,17...Fastening part 2...Automobile body 21...Underbody 22...Dash panel 23...Front floor panel 24...Rear floor panel 25...Sill 3...Battery 31...Battery module 4...Dispensing nozzle S...Seam P1...Dispensing start point P2...Dispensing end point H1,H2...Height T...Triangle L1...Extension of the center of the cross member M1,M2,M3,M4...Seam placement range

Claims

1. A vehicle battery pack comprising: a lower case having a cross member extending in the vehicle width direction and on which a battery is mounted at the bottom, and having an open top surface; an upper case covering the opening of the lower case and fastened to the lower case at the outer circumference of the lower case and the cross member; and a coating-type sealing member arranged along the entire circumference of the outer circumference of the lower case and sandwiched between the outer circumference and the upper case to seal the space between the lower case and the upper case, wherein the seam of the sealing member is defined by the fastening portion between the cross member and the upper case, and two fastening portions between the outer circumference and the upper case that straddle the extension line of the center of the cross member, and is provided on the line of a triangle and on the inner outer circumference in a plan view of the vehicle.

2. The vehicle battery pack according to claim 1, wherein the sealing member comprises two sealing members arranged in parallel.

3. The vehicle battery pack according to claim 2, wherein the joint of one of the two sealing members is provided on the outer circumference of one end of the cross member, and the joint of the other sealing member is provided on the outer circumference of the other end of the cross member.

4. The joint between the two sealing members is provided on the outer circumference of one end or the other end of the cross member, as described in claim 2.

5. The vehicle battery pack according to any one of claims 1 to 4, wherein the joint of the sealing member is provided on the outer circumference on the extension line of the cross member.

6. The vehicle battery pack according to any one of claims 1 to 5, wherein the joint of the sealing member is provided on the outer circumference corresponding to the area between the front and rear ends of the sill of the vehicle along the longitudinal direction of the vehicle.

7. The vehicle battery pack according to any one of claims 1 to 6, wherein the joint of the sealing member is provided on the outer circumference above the fastening portion between the sill of the vehicle and the lower case in the vertical direction of the vehicle.

8. The vehicle battery pack according to any one of claims 1 to 7, wherein the coating-type sealing member includes a joint where the coating start point and the coating end point overlap along the coating direction, with the coating end point located behind the coating start point in the front-rear direction of the vehicle.

9. The vehicle battery pack according to any one of claims 1 to 7, wherein the coating-type sealing member includes a joint where the coating start point and the coating end point overlap along the coating direction, with the coating end point located in front of the coating start point in the front-rear direction of the vehicle.

10. A vehicle battery pack according to any one of claims 1 to 9, which is mounted under the floor of the vehicle.

11. A vehicle having a vehicle battery pack according to any one of claims 1 to 9 mounted under the floor.

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