Sealing structure of battery pack case

Abstract

The present invention provides a battery pack comprising: an upper case; a lower case coupled to the upper case; a sealing member for sealing a gap between the upper case and the lower case, wherein the sealing member is a closed-curve shaped component interposed between an edge portion of the upper case and an edge portion of the lower case; and a coupling member for coupling the edge portion of the upper case and the edge portion of the lower case. The coupling member includes a coupling protrusion protruding toward the upper case side compared to the edge portion of the lower case, and the sealing member includes a coupling hole into which the coupling protrusion is inserted.

Description

Sealing structure of the battery pack case

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0197776, dated December 29, 2023, and Korean Patent Application No. 10-2024-0029097, dated February 28, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a sealing structure of a battery pack case, and more specifically, to a structure capable of simply and firmly sealing and fixing the lower case and upper case of a battery pack by interposing a sealing member.

[0003] Secondary batteries are rechargeable batteries that have high energy density and diverse usability, and are used in portable devices, automobiles, and power storage devices that require power supply.

[0004] Secondary batteries are based on battery cells, which can take on various shapes, including cylindrical, prismatic, and pouch-shaped. These cells can be integrated into devices, either individually or in multiples. In particular, electric and hybrid vehicles, which rely on electricity as their power source, require high output and capacity. Therefore, it's common to incorporate battery modules or packs containing multiple integrated battery cells.

[0005] A typical battery pack comprises a case in which multiple battery cells or battery modules are integrated and housed. A particularly popular case structure is one in which an upper case and a lower case are combined.

[0006] Figures 1 and 2 illustrate the structure of a conventional battery pack. Referring to these drawings, a conventional battery pack (1) is configured by housing battery cells or battery modules in an upper case (11) and a lower case (12). At this time, it is common for the upper case (11) and the lower case (12) to have a sealing member (13) interposed therebetween for sealing them for watertightness inside and outside thereof. This sealing member (13) includes a gasket made of a compressible material, and is pressurized and sealed between the upper case (11) and the lower case (12) by a fastening member (14) that fastens the cases (11, 12).

[0007] Fig. 3 shows a cross-section of the battery pack of Fig. 1. Referring to this, the fastening member (14) includes a bolt (B) penetrating the upper case (11) and the lower case (12) and a nut (N) fastened to the bolt (B). At this time, the sealing member (13) includes a fastening hole (130) and an annular fastening member (131) fitted into the fastening hole (130), and the bolt (B) penetrates the fastening member (131) so that the position of the sealing member (13) is regulated.

[0008] In order to assemble a battery pack (1) having such a structure, the sealing member (13) and the upper case (11) must be aligned so as to overlap appropriately on the lower case (12), and the bolt (B) must be inserted so as to penetrate the cases (11, 12) and the connecting member (131) simultaneously. This fastening process must be performed simultaneously and in a balanced manner at multiple locations arranged along the circumferential direction of the edge portion of the cases (11, 12).

[0009] In addition, since the conventional bonding structure as described above requires a process of mounting the bonding member (131) on the sealing member (13) prior to the fastening process as described above, the manufacturing of the sealing member (13) is difficult and the unit cost is very high.

[0010] In other words, a battery pack (1) having this type of structure is very cumbersome and inconvenient to assemble, requires an excessive number of parts and processes, and has a high manufacturing cost.

[0011] In addition, such a sealing structure is also disadvantageous for ensuring watertightness of the battery pack (1). For example, if the connecting member (131) is not precisely aligned with the center of the bolt (B) and the nut (N), the compressive force is applied unevenly along the circumference of the bolt (B), and the area where the compressive force is applied less has relatively weak watertightness.

[0012] Accordingly, there is an urgent need to propose a sealed structure for a battery pack case that is easy to assemble, easy to align, and can ensure sufficient watertightness.

[0013] The present invention was created under the background of the above-described prior art, and its purpose is to provide a structure of a battery pack having improved sealing properties inside and outside the case.

[0014] Another technical challenge of the present invention is to provide a structure of a battery pack that can achieve fastening and sealing of a case through a simple process.

[0015] To this end, the present invention seeks to provide a sealing structure of a battery pack in which a sealing member can be easily mounted in an accurate position.

[0016] In addition, the present invention seeks to provide a battery pack structure that ensures sufficient sealing while requiring fewer parts and materials.

[0017] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0018] The present invention can be applied to a battery pack in which a sealing member is interposed between a first coupling surface of a first case and a second coupling surface of a second case, and the first case and the second case are fastened so that the first coupling surface and the second coupling surface are in close contact with each other, thereby compressing the sealing member.

[0019] The above first case and the above second case can be mutually fastened by a fastening member.

[0020] The above first case may have a first frame portion provided with the first bonding surface.

[0021] The second case may have a second frame portion provided with the second bonding surface.

[0022] The above sealing member can be compressed and interposed between the first and second joining surfaces facing each other to seal the joining portion of the first edge portion and the second edge portion.

[0023] The above fastening member can be fastened in a direction in which the first edge portion and the second edge portion are in close contact with each other.

[0024] The above fastening member includes a bolt and a nut that are fastened to each other.

[0025] The above fastening member further includes a joining projection.

[0026] The above-mentioned coupling protrusion is arranged on the first coupling surface side, fixed to the first edge portion, and protrudes from the first coupling surface.

[0027] The above-mentioned joining projection can be formed as one member with the first edge portion.

[0028] Any one of the above nuts and bolts may be formed as one member with the first edge portion.

[0029] The above-mentioned coupling projection can be formed as one member with the first fastening member selected from among the above-mentioned nuts and bolts.

[0030] The above-mentioned coupling protrusion can be connected to a first fastening member selected from among the above-mentioned nuts and bolts through a first hole of the above-mentioned first edge portion.

[0031] The second fastening member, which is the remaining one of the above nuts and bolts, can be fastened with the first fastening member.

[0032] The cross-section defined by the outer circumference of the above-mentioned coupling protrusion may be larger than the cross-section defined by the inner circumference of the above-mentioned first hole.

[0033] The cross-section defined by the outer circumference of the first fastening member may be smaller than the cross-section defined by the inner circumference of the first hole.

[0034] The above-mentioned coupling protrusion and the first fastening member can be interconnected by a connecting portion penetrating the first hole.

[0035] The above connecting portion may have a fixing portion that is positioned between the first back surface, which is an opposite surface of the first joining surface of the first edge portion, and the first fastening member and extends radially outward.

[0036] The cross-section defined by the outer circumference of the above-mentioned fixed portion may be larger than the cross-section defined by the inner circumference of the above-mentioned first hole.

[0037] The above fixed portion may be defined by a portion of the connecting portion disposed between the nut and the first edge portion that is axially compressed and deformed.

[0038] The above sealing member has an inner surface that is in contact with the outer surface of the coupling protrusion and a coupling hole into which the coupling protrusion is fitted.

[0039] The above sealing member can be easily mounted at an accurate position on the first edge portion of the first case by being fitted into the above coupling projection.

[0040] A fastening member in a specific implementation form includes a fastening projection fixed to the first edge portion and positioned toward the first engagement surface so as to protrude from the first engagement surface and aligned with a first hole of the first edge portion, a nut fixed to the first edge portion and aligned with the first hole, and a bolt penetrating the fastening projection and the first hole and fastened to the nut.

[0041] The above nut is placed on the first back side, and the coupling protrusion can be connected to the nut through the first hole.

[0042] The cross-section defined by the outer circumference of the above-mentioned coupling protrusion may be larger than the cross-section defined by the inner circumference of the above-mentioned first hole.

[0043] The cross-section defined by the outer circumference of the above nut may be smaller than the cross-section defined by the inner circumference of the above first hole.

[0044] The above nut and the above coupling projection can be interconnected by a connecting portion penetrating the first hole.

[0045] The above connecting portion may have a fixing portion that is positioned between the first back surface of the first edge portion and the nut and extends radially outward.

[0046] The cross-section defined by the outer circumference of the above-mentioned fixed portion may be larger than the cross-section defined by the inner circumference of the above-mentioned first hole.

[0047] The above fixed portion may be defined by a portion of the connecting portion disposed between the nut and the first edge portion that is axially compressed and deformed.

[0048] The bolt may penetrate the second hole of the second edge portion, and the head of the bolt may be positioned on the second back surface of the second edge portion facing the second joining surface.

[0049] A specific other implementation form of the fastening member may include a fastening projection fixed to the first edge portion and positioned toward the first engagement surface so as to protrude from the first engagement surface, a bolt fixed to the first edge portion and aligned with the fastening projection and penetrating a second hole of the second edge portion, and a nut disposed on a second back surface side of the second edge portion facing the second engagement surface and fastened to the bolt.

[0050] The head of the bolt is positioned on the first back side, and the coupling protrusion can be connected to the head of the bolt through the first hole.

[0051] The cross-section defined by the outer circumference of the above-mentioned coupling protrusion may be larger than the cross-section defined by the inner circumference of the above-mentioned first hole.

[0052] The cross-section defined by the outer circumference of the head may be smaller than the cross-section defined by the inner circumference of the first hole.

[0053] The above head and the above coupling protrusion can be interconnected by a connecting portion penetrating the first hole.

[0054] The above connecting portion may have a fixing portion that is positioned between the first back surface of the first edge portion and the head and extends radially outward.

[0055] The cross-section defined by the outer circumference of the above-mentioned fixed portion may be larger than the cross-section defined by the inner circumference of the above-mentioned first hole.

[0056] The above fixed portion may be defined by a portion of the connecting portion disposed between the head and the first edge portion that is axially compressed and deformed.

[0057] The above bolt can penetrate the first hole of the first edge portion and the coupling protrusion.

[0058] Meanwhile, the sealing member may have a first sealing rib protruding from at least one of a first surface facing the first coupling surface and a second surface facing the second coupling surface and extending along the longitudinal direction of the sealing member.

[0059] The sealing member may have a second sealing rib protruding from at least one of the first and second surfaces and extending in a closed loop shape along the perimeter of the joining groove.

[0060] The longitudinal end of the first sealing rib can be connected to the second sealing rib.

[0061] The first sealing ribs are provided in plurality, and the plurality of first sealing ribs can be arranged to be spaced apart from each other in the width direction of the sealing member.

[0062] The second sealing ribs are provided in plurality, and the plurality of second sealing ribs can be arranged concentrically and spaced apart from each other in the radial direction.

[0063] In the above sealing member, the width of the portion where the joining hole is provided may be larger than that of the remaining portion.

[0064] In one implementation example, the first case may be a lower case, and the second case may be an upper case covering an open upper portion of the lower case.

[0065] The above fastening member may include: a nut provided on the edge of the lower case; and a bolt that penetrates the edge of the upper case and is fastened to the nut. In this case, the coupling protrusion may be included in the nut.

[0066] The above nut, despite its name, may be formed as one piece with the lower case, or may be fixed to the rim of the lower case as a separate piece.

[0067] The nut may have a fixing portion that interposes the lower case between the coupling projection and the lower case. For example, the nut may have a pop nut structure. In this case, the fixing portion may be formed by compressively deforming a connecting portion that passes through the lower case.

[0068] By fixing the above nut to the lower case, the coupling protrusion can also be fixed at an accurate position on the edge of the lower case, and the sealing member can also be mounted at an accurate position.

[0069] The above fastening member may include: a bolt provided on the edge of the lower case so as to penetrate the upper case; and a nut fastened to the bolt. In this case, the coupling protrusion may be included in the bolt.

[0070] The above bolt, despite its name, may be formed as one piece with the lower case, or may be fixed to the rim of the lower case as a separate piece.

[0071] The bolt may have a fixing portion that interposes the lower case between the coupling protrusion and the bolt. For example, the bolt may have a pop bolt structure. In this case, the fixing portion may be formed by compressively deforming a connecting portion that passes through the lower case.

[0072] By fixing the above bolt to the lower case, the coupling protrusion can also be fixed at an accurate position on the edge of the lower case, and the sealing member can also be mounted at an accurate position.

[0073] The sealing member may be provided with a first sealing rib that extends along its extension direction to a predetermined width and protrudes in one or both directions in its thickness direction. At this time, the first sealing rib may be in direct contact with the upper case and / or the lower case and may be compressed. By providing the first sealing rib, the sealing member may be compressed at a higher pressure for the same fastening force by being pressed in a smaller area, thereby sealing the upper case and the lower case more strongly.

[0074] The sealing member may be provided with a second sealing rib extending along the circumference of the coupling groove to a predetermined width and protruding in one or both directions in the thickness direction thereof. At this time, the second sealing rib may be in direct contact with the upper case and / or the lower case and may be compressed. By providing the second sealing rib, the sealing member may be compressed at a higher pressure for the same fastening force by being pressed in a smaller area. Accordingly, the second sealing rib may seal between the upper case and the lower case and at the same time seal the fastening portion through which the fastening member penetrates, thereby improving the sealing property of the battery pack.

[0075] The first sealing rib and / or the second sealing rib may be formed to be pressed in a narrower area, including a tapered shape whose width becomes smaller as it goes outward in the thickness direction.

[0076] The first sealing rib and / or the second sealing rib may be provided in multiple numbers. Accordingly, the sealing between the upper case and the lower case may be multiple and stable.

[0077] In the above sealing member, it is preferable that the width of the portion where the joining hole is provided be larger than that of the remaining portion. Since the width of the sealing member does not need to be large in the portion where the joining hole is not provided, this can reduce the use of unnecessary materials.

[0078] The present invention can provide a structure of a battery pack in which the inside and outside are completely sealed by a sealing member that is compressed between a first case and a second case (upper case and lower case) by a fastening member.

[0079] According to the present invention, the mounting position of the sealing member is accurately guided and regulated by the joining projection, thereby providing a structure of a battery pack that is easy to assemble.

[0080] Another advantage of the present invention lies in providing a structure of a battery pack in which sealing and fastening of the case are achieved using a minimum of materials and parts.

[0081] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0082] Figures 1 and 2 show the structure of a conventional battery pack.

[0083] Figure 3 shows a cross-section of the battery pack of Figure 1.

[0084] Figures 4 and 5 illustrate the structure of a battery pack according to one embodiment of the present invention.

[0085] FIG. 6 shows a cross-section of a lower case according to one embodiment of the present invention with a first nut and a first bolt mounted thereon.

[0086] Figure 7 shows a sealing member coupled to a lower case according to one embodiment of the present invention.

[0087] Figure 8 shows a cross-section of a battery pack and its sealing structure according to one embodiment of the present invention.

[0088] Figure 9 shows another cross-section of a battery pack and its sealing structure according to one embodiment of the present invention.

[0089] [Explanation of symbols]

[0090] 1: Battery pack

[0091] 11: Upper case

[0092] 12: Lower case

[0093] 13: Sealing member

[0094] 130: Combination hole

[0095] 131: Joining member

[0096] 14: Absence of fasteners

[0097] B: Bolt

[0098] N: Nut

[0099] 2: Battery pack

[0100] 21: Upper case

[0101] 210: Border

[0102] 22: Lower case

[0103] 220: Border

[0104] 23: Sealing member

[0105] 230: Combination hole

[0106] 231: First sealing rib

[0107] 232: Second sealing rib

[0108] 24: Absence of a binding

[0109] 240: Connection

[0110] 241: Combination protrusion

[0111] 242: Fixed part

[0112] N1: First nut

[0113] N2: Second nut

[0114] B1: First bolt

[0115] B2: Second bolt

[0116] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0117] The present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and with various modifications. However, these embodiments are provided to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Therefore, the present invention is not limited to the embodiments disclosed below, but should be understood to include all modifications, equivalents, and substitutes included within the technical spirit and scope of the present invention, as well as substitutions or additions of the components of one embodiment with those of another embodiment.

[0118] The attached drawings are only intended to facilitate understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention. In the drawings, the components may be expressed in an exaggerated size or thickness for convenience of understanding, etc., but the scope of protection of the present invention should not be construed as being limited due to this.

[0119] The terminology used in this specification is only used to describe specific implementations or examples and is not intended to limit the present invention. In addition, the singular expression includes the plural expression unless the context clearly indicates otherwise. In the specification, terms such as "comprises" and "consists of" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification. In other words, it should be understood that terms such as "comprises" and "consists of" in the specification do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0120] Terms that include ordinal numbers, such as "first," "second," etc., may be used to describe various components, but these components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0121] When a component is referred to as being "connected" or "in contact with" another component, it should be understood that it may be directly connected or in contact with that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "in contact with" another component, it should be understood that there are no other components intervening.

[0122] When a component is referred to as being "above" or "below" another component, it should be understood that it is not only positioned directly above that other component, but that there may also be other components present in between.

[0123] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0124] Although this embodiment exemplifies a sealing structure of a battery pack case including an upper case and a lower case, it will be understood from the following description that the problem-solving method of the present invention can be applied not only to a battery pack case of this type but also to any case formed by combining two or more members for sealing.

[0125] Figures 4 and 5 illustrate the structure of a battery pack according to one embodiment of the present invention. Referring to these drawings, a battery pack (2) according to one embodiment of the present invention may include a case that accommodates one or more battery cells and / or battery modules. The case may include an upper case (21) and a lower case (22).

[0126] The upper case (21) and the lower case (22) can be joined together by fastening their edges (210, 220) to each other.

[0127] The above-mentioned edge portion may be in the form of a flange extending outward from the edge of the case. The edge portion of the upper case and the edge portion of the lower case each include a coupling surface facing each other in the vertical direction and a back surface facing the coupling surface.

[0128] For convenience of explanation, the rim of the upper case is referred to as the upper rim, the joining surface of the upper rim is referred to as the upper joining surface, the back surface of the upper rim is referred to as the upper back surface, and the hole formed in the upper rim is referred to as the upper hole. In addition, the rim of the lower case is referred to as the lower rim, the joining surface of the lower rim is referred to as the lower joining surface, the back surface of the lower rim is referred to as the lower back surface, and the hole formed in the lower rim is referred to as the lower hole.

[0129] A sealing member (23) for sealing between the upper case (21) and the lower case (22) may be interposed between the above-mentioned frame portions (210, 220). The sealing member is a closed-loop-shaped member extending along the above-mentioned frame portions (210, 220) and may have a compressible material.

[0130] The above sealing member (23) has an upper surface and a lower surface facing the joining surfaces of the two cases, respectively.

[0131] The upper case (21) and the lower case (22) can be joined through a joining member (24) that joins the rim portions (210, 220). Accordingly, the sealing member (23) is pressed and compressed between the rim portions (210, 220), thereby sealing the area between the joining surface of the rim portion of the upper case (21) and the joining surface of the rim portion of the lower case (22).

[0132] For convenience of explanation, the direction in which the upper edge portion and the lower edge portion are in close contact with each other by the fastening member is referred to as the fastening direction or axial direction, the direction surrounding the axis is referred to as the circumferential direction, and the direction approaching or moving away from the axis is referred to as the radial direction or radial direction.

[0133] Fig. 6 illustrates a cross-section of a lower case according to one embodiment of the present invention, wherein a first nut and a first bolt are mounted. Referring to these drawings, a coupling protrusion (241) may be provided on the lower case (22) that protrudes toward the upper case (21) compared to the edge portion (220) of the lower case (22). The coupling protrusion (241) may be provided integrally with the lower case (22) or may be mounted separately. In addition, the coupling protrusion (241) may be included in the fastening member (24) or may be provided separately therefrom.

[0134] A first nut (N1) may be provided on the edge portion (220) of the lower case (22). The first nut (N1) may be formed as a single member with the lower case (22), or may be a separate member mounted on the lower case (22). In this case, the coupling protrusion (241) may be included in the first nut (N1).

[0135] According to one embodiment of the present invention, the first nut (N1) may be a separate nut mounted on the edge portion (220) of the lower case (22). At this time, the first nut (N1) may be provided with a fixing portion (242), and the first nut (N1) may be fixed to the lower case (22) by interposing the lower case (22) between the coupling protrusion (241) and the fixing portion (242).

[0136] According to one embodiment of the present invention, the first nut (N1) may be implemented as a nut that is inserted into a fixed object and then compressed and deformed to be fixed to the fixed object. To this end, the first nut (N1) according to one embodiment of the present invention may include a fixed portion (242) that is compressed and deformed after passing through the lower case (22).

[0137] As the first nut (N1) is fixed to the lower case (22), the process of aligning the fastening member (24) to the exact position on the lower case (22) and the upper case (21) can be omitted.

[0138] In a preferred embodiment, the coupling protrusion (241) is positioned on the lower coupling surface so as to protrude upward from the lower coupling surface, and the first nut (N1) is positioned on the lower side of the lower surface. In addition, the coupling protrusion (241) and the first nut (N1) are interconnected through a tubular connecting portion (240) that penetrates the lower edge portion (220) through a lower hole.

[0139] When viewed in the axial direction, the cross-section of the engaging projection (241) defined by the outer circumference of the engaging projection is larger than the cross-section of the lower hole defined by the inner circumference of the lower hole. In addition, the cross-section of the first nut (N1) defined by the outer circumference of the first nut is smaller than the cross-section of the lower hole. In addition, the cross-section of the connecting portion defined by the outer circumference of the connecting portion (240) is slightly smaller than the cross-section of the lower hole by almost the same amount.

[0140] By inserting the first nut (N1) and the connecting portion (240) through the lower hole from the upper portion of the lower frame portion (220), the lower surface of the connecting projection (241) can be brought into contact with the lower connecting surface. At this time, by the guidance of the inner surface of the lower hole and the outer surface of the connecting portion (240), the connecting projection (241) can be aligned very simply and accurately with the lower hole.

[0141] Next, while the above-mentioned coupling protrusion (241) is pressed downward, the first nut (N1) is pulled upward through the lower hole. Then, the connecting portion (240) section provided between the lower surface and the first nut (N1) in the axial direction is less rigid than the first nut, so it is buckled outward in the radial direction, forming a fixed portion (242) with an expanded outer diameter.

[0142] Then, the alignment state of the coupling protrusion (241) for aligning the sealing member (23) is maintained, while the first nut (N1) can be simply fixed to the lower edge portion (220).

[0143] In contrast to the coupling projection (241), the first nut (N1) does not need to be strictly aligned with the lower hole. If the inner diameters of the lower hole and the upper hole are set to be larger than the inner diameter of the tap hole of the first nut (N1), a slight misalignment can be sufficiently absorbed.

[0144] Meanwhile, a first bolt (B1) extending to penetrate the upper case (21) may be provided on the edge portion (220) of the lower case (22). The first bolt (B1) may be formed as a single member with the lower case (22), or may be a separate member mounted on the lower case (22). In this case, the coupling protrusion (241) may be included in the first bolt (B1).

[0145] According to one embodiment of the present invention, the first bolt (B1) may be a separate bolt mounted on the edge portion (220) of the lower case (22). At this time, the first bolt (B1) may have a fixing portion (242), and the first bolt (B1) may be fixed to the lower case (22) by interposing the lower case (22) between the coupling protrusion (241) and the fixing portion (242).

[0146] According to another embodiment of the present invention, the first bolt (B1) may be implemented as a bolt that is inserted into a fixed object and then compressed and deformed to fit the fixed object. To this end, the first bolt (B1) according to one embodiment of the present invention may include a fixing portion (242) that is compressed and deformed after passing through the lower case (22).

[0147] As the first bolt (B1) is fixed to the lower case (22), the process of aligning the fastening member (24) to the exact position on the lower case (22) and the upper case (21) can be omitted.

[0148] In a preferred embodiment, the coupling protrusion (241) is positioned on the lower coupling surface so as to protrude upward from the lower coupling surface, and the first bolt (B1) is positioned on the lower side of the lower surface. In addition, the coupling protrusion (241) and the first bolt (B1) are interconnected through a connecting portion (240) that penetrates the lower edge portion (220) through a lower hole. The lower end of the connecting portion (240) is connected to the head of the first bolt (B1).

[0149] When viewed in the axial direction, the cross-section of the coupling projection is larger than the cross-section of the lower hole, the head cross-section defined by the outer circumference of the head of the first bolt (B1) is smaller than the cross-section of the lower hole, and the cross-section of the connecting portion is slightly smaller than the cross-section of the lower hole by almost the same amount.

[0150] The head of the first bolt (B1) and the connecting portion (240) can be inserted through the lower hole from the upper portion of the lower frame portion (220) so that the bottom surface of the connecting projection (241) is in contact with the lower connecting surface. At this time, by the guidance of the inner surface of the lower hole and the outer surface of the connecting portion (240), the connecting projection (241) can be aligned very simply and accurately with the lower hole.

[0151] Next, while the above-mentioned coupling protrusion (241) is pressed downward, the head of the first bolt (B1) is pulled upward through the lower hole. Then, the section of the connecting portion (240) provided between the lower surface and the head of the first bolt (B1) in the axial direction is less rigid than the head of the first bolt, so that it is buckled outward in the radial direction, thereby forming a fixed portion (242) with an expanded outer diameter.

[0152] Then, the alignment state of the coupling protrusion (241) for aligning the sealing member (23) is maintained, while the first bolt (B1) can be simply fixed to the lower edge portion (220).

[0153] In contrast to the coupling protrusion (241), the first bolt (B1) does not need to be strictly aligned with the lower hole. If the inner diameters of the lower hole and the upper hole are set to be larger than the outer diameter of the threaded portion of the first bolt (B1), a slight misalignment can be sufficiently absorbed.

[0154] The battery pack (2) may include at least one of the first nut (N1) and the first bolt (B1). Preferably, the battery pack (2) according to one embodiment of the present invention includes both the first nut (N1) and the first bolt (B1).

[0155] Fig. 7 illustrates a state in which a sealing member is coupled to a lower case according to one embodiment of the present invention. Referring to this, a coupling hole (230) into which the coupling protrusion (241) is fitted may be provided in the sealing member (23). The coupling hole (230) may be provided to correspond to the coupling protrusion (241) of the first nut (N1) and / or the first bolt (B1) provided along the edge portion (220) of the lower case (22), and may be repeatedly arranged at a predetermined interval along the extension direction of the sealing member (23).

[0156] According to the present embodiment, the sealing member (23) can be mounted at an appropriate position on the lower case (22) by fitting the coupling protrusion (241) into the coupling hole (230). Accordingly, a separate member for aligning the position of the sealing member (23) with respect to the lower case (22) is not required, and the sealing member (23) can be mounted at an accurate position even before the fastening between the upper case (21) and the lower case (22).

[0157] The sealing member (23) may include a first sealing rib (231). The first sealing rib (231) has a predetermined width and extends along the extension direction of the sealing member (23), and may protrude in one or both directions in the thickness direction from the upper surface or / and the lower surface of the sealing member (23).

[0158] The above first sealing ribs (231) may be provided in multiple numbers, may be spaced apart from each other in the width direction, and may have their longitudinal ends connected to the second sealing ribs (232) described later. The embodiment exemplifies that three first sealing ribs (231) are provided.

[0159] The sealing member (23) may include a second sealing rib (232). The second sealing rib (232) has a predetermined width and extends along the perimeter of the coupling groove, and may protrude in one or both directions in the thickness direction from the upper surface or / and the lower surface of the sealing member (23).

[0160] The second sealing ribs (232) may be provided in multiple numbers, and may be arranged concentrically and radially spaced apart from each other. The outermost second sealing rib (232) is connected to the first sealing rib (231). The embodiment exemplifies that two second sealing ribs (232) are provided.

[0161] In the above sealing member (23), it is preferable that the width of the area where the joining hole (230) is provided be larger than that of the remaining area. Accordingly, the sealing member (23) may not unnecessarily consume its volume and materials.

[0162] Fig. 8 shows a cross-section of a battery pack according to one embodiment of the present invention and its sealing structure. Referring to this, the upper case (21) and the lower case (22) can be fastened by a first bolt (B1) penetrating the lower hole and the engaging protrusion and the upper hole, and a second nut (N2) fastened to the first bolt (B1) on the upper back surface of the upper case (21). Accordingly, the sealing member (23) can be pressed by the upper engaging surface and the lower engaging surface between the rim portions (210, 220) to seal the upper rim portion (210) of the upper case (21) and the lower rim portion (220) of the lower case (22).

[0163] Fig. 9 shows another cross-section of a battery pack according to one embodiment of the present invention and its sealing structure. Referring to this, the upper case (21) and the lower case (22) can be fastened by a first nut (N1) arranged on the lower back surface and a second bolt (B2) that penetrates the upper hole, the coupling protrusion, and the lower hole from the upper portion of the upper case (21) and is fastened to the first nut (N1). Accordingly, the sealing member (23) can be pressed by the upper coupling surface and the lower coupling surface between the rim portions (210, 220) to seal the upper rim portion (210) of the upper case (21) and the lower rim portion (220) of the lower case (22).

[0164] The first sealing rib (231) and the second sealing rib (232) can be compressed by directly contacting the edges (210, 220) of the upper case (21) and the lower case (22). Accordingly, the sealing member (23) can be compressed at a higher pressure in a smaller area, and can more strongly seal between the upper case (21) and the lower case (22) and between the upper case (21), the lower case (22), and / or the fastening member (24).

[0165] The first sealing rib (231) and the second sealing rib (232) above have a tapered shape whose width becomes smaller as they go outward in the thickness direction, so that the pressurized area can be formed smaller.

[0166] In addition, the first sealing rib (231) and the second sealing rib (232) are provided in multiple numbers, so that the sealing of the battery pack (2) can be stable and multiple.

[0167] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. A first case having a first frame portion provided with a first bonding surface; A second case having a second frame portion provided with a second bonding surface facing the first bonding surface; A sealing member that seals the joint portion of the first edge portion and the second edge portion by being press-fitted between the first and second joint surfaces facing each other; and Including a fastening member that fastens the first edge portion and the second edge portion in a direction in which they are in close contact with each other; The above fastening member is: A coupling protrusion fixed to the first edge portion and positioned toward the first coupling surface so as to protrude from the first coupling surface, and aligned with the first hole of the first edge portion; A nut fixed to the first edge portion and aligned with the first hole; and A bolt penetrating the above-mentioned joining projection and the first hole and fastened to the nut; A battery pack, wherein the sealing member has an inner surface that comes into contact with the outer surface of the coupling protrusion and a coupling hole into which the coupling protrusion is fitted.

2. In claim 1, The above nut is placed on the first back surface of the first edge portion facing the first joining surface, A battery pack, wherein the above-mentioned coupling projection is connected to the nut through the first hole.

3. In claim 2, A battery pack, wherein the above nut and the above coupling projection are interconnected by a connecting portion penetrating the first hole.

4. In claim 3, A battery pack, wherein the above connecting portion has a fixing portion that is positioned between the first surface of the first edge portion and the nut and extends radially outward.

5. In claim 4, A battery pack, wherein a cross-section defined by the outer perimeter of the above-mentioned fixed portion is larger than a cross-section defined by the inner perimeter of the above-mentioned first hole.

6. In claim 4, A battery pack, wherein the above-mentioned fixed portion is defined by a portion in which a connecting portion section disposed between the nut and the first edge portion is axially compressed and deformed.

7. In claim 1, A battery pack, wherein a cross-section defined by an outer circumference of the above-mentioned coupling protrusion is larger than a cross-section defined by an inner circumference of the above-mentioned first hole.

8. In claim 1, A battery pack, wherein a cross-section defined by an outer circumference of the above nut is smaller than a cross-section defined by an inner circumference of the above first hole.

9. In claim 1, A battery pack, wherein the bolt penetrates the second hole of the second edge portion, and the head of the bolt is positioned on the second back surface of the second edge portion facing the second joining surface.

10. A first case having a first frame portion provided with a first bonding surface; A second case having a second frame portion provided with a second bonding surface facing the first bonding surface; A sealing member that seals the joint portion of the first edge portion and the second edge portion by being press-fitted between the first and second joint surfaces facing each other; and Including a fastening member that fastens the first edge portion and the second edge portion in a direction in which they are in close contact with each other; The above fastening member is: A coupling projection fixed to the first edge portion and positioned toward the first coupling surface so as to protrude from the first coupling surface; A bolt fixed to the first edge portion, aligned with the coupling projection, and penetrating the second hole of the second edge portion; A nut is disposed on the second back surface of the second edge portion facing the second joining surface and is fastened to the bolt; A battery pack, wherein the sealing member has an inner surface that comes into contact with the outer surface of the coupling protrusion and a coupling hole into which the coupling protrusion is fitted.

11. In claim 10, The head of the above bolt is positioned on the first back surface of the first edge portion facing the first joining surface, A battery pack, wherein the above-mentioned coupling projection is connected to the head of the bolt through the first hole.

12. In claim 11, A battery pack, wherein the head and the coupling projection are interconnected by a connecting portion penetrating the first hole.

13. In claim 12, A battery pack, wherein the above connecting portion has a fixing portion that is positioned between the first surface of the first edge portion and the head and extends radially outward.

14. In claim 13, A battery pack, wherein a cross-section defined by the outer perimeter of the above-mentioned fixed portion is larger than a cross-section defined by the inner perimeter of the above-mentioned first hole.

15. In claim 14, A battery pack, wherein the above-mentioned fixed portion is defined by a portion in which a connecting portion section disposed between the head and the first edge portion is axially compressed and deformed.

16. In claim 10, A battery pack, wherein a cross-section defined by the outer perimeter of the above-mentioned coupling projection is larger than a cross-section defined by the inner perimeter of the first hole of the above-mentioned first rim portion.

17. In claim 10, A battery pack, wherein a cross-section defined by the outer circumference of the head of the above bolt is smaller than a cross-section defined by the inner circumference of the first hole of the above first rim portion.

18. In claim 10, A battery pack, wherein the bolt penetrates the first hole of the first frame and the joining projection.

19. In any one of claims 1 to 18, The above sealing member: A first sealing rib protruding from at least one of a first surface facing the first joining surface and a second surface facing the second joining surface and extending along the longitudinal direction of the sealing member; and A second sealing rib is provided which protrudes from at least one of the first and second surfaces and extends in a closed loop shape along the perimeter of the joining groove; A battery pack, wherein a longitudinal end of the first sealing rib is connected to the second sealing rib.

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