Battery pack

Abstract

The present invention relates to a battery pack, and the battery pack of the present invention accommodates a battery module including a cell stack in which a plurality of cells are stacked, and is characterized in that it includes: a base plate supporting a lower part of the battery module; a pack case including a main partition wall coupled to a center of the base plate and extending across the base plate; a side wall coupled along an edge of the base plate; and an auxiliary partition wall whose both ends are coupled to the main partition wall and the side wall, respectively; and a long bolt member coupled to the pack case through the auxiliary partition wall so that the auxiliary partition wall is coupled to the main partition wall and the side wall.

Description

[Technical Field]

[0001] The present invention relates to a battery pack, and more specifically, the battery pack of the present invention is characterized in that a bolt is inserted from a side of a pack case toward an auxiliary partition wall to fix the auxiliary partition wall installed between battery modules to separate the battery modules, and the inserted bolt improves the lateral support force of the battery modules.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0084652, filed on July 8, 2022, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [Background technology]

[0003] Types of secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such a unit secondary battery cell, i.e., a unit battery cell, is approximately 2.5V to 4.2V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting a plurality of battery cells in series. Alternatively, a battery pack may be configured by connecting a number of battery cells in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack may be variously set depending on the required output voltage or charge / discharge capacity.

[0004] For example, when a battery pack is constructed by connecting a plurality of battery cells in series / parallel, a battery module made up of the plurality of battery cells is first constructed.

[0005] FIG. 1 shows a commonly used battery module 10 and a pack case 20 included in a battery pack that houses the battery module 10.

[0006] 1(a) shows one form of a battery module 10. As shown in the figure, a conventional battery module 10 has end plates 11 attached to the front and rear ends, and the sides are surrounded and protected by a module frame 12. In recent years, battery modules 10 in which the module frame 12 is eliminated and the internal cells are exposed have also been used.

[0007] 1(b) shows a pack case 20 in a typical battery pack that provides a space for accommodating battery modules 10. In the pack case 20 shown in FIG. 1(b), each battery module 10 is supported at its lower part by a base plate 21 in a space partitioned by a main partition wall 23 and an auxiliary partition wall 24, and is electrically connected to other battery modules 10 in series or parallel.

[0008] The battery module 10 included in the battery pack may experience abnormal phenomena during charging and discharging, one example of which is swelling. The swelling is a phenomenon in which a battery cell expands due to gas generated inside the battery cell. The swelling may occur first in each battery cell housed in the battery module 10, thereby affecting the battery module 10.

[0009] Generally, each battery module 10 housed in a pack case 20 may have its sides supported by auxiliary partitions 24 as shown in FIG. 1(b). However, since the auxiliary partitions 24 are not installed for the purpose of preventing swelling, they may be damaged due to being unable to withstand the expansion force of the battery module 10 that causes swelling.

[0010] Meanwhile, the plurality of battery modules 10 housed in the battery pack may be separated by auxiliary partitions 24, which may be screwed to the base plate 21 or may be joined to the base plate 21 by welding a welding portion Aw that is the boundary between the auxiliary partitions 24 and the base plate 21.

[0011] However, in the case of the above-mentioned welded structure, there is a possibility that the base plate 21 or the auxiliary partition wall 24 may bend or twist due to the welding heat, and there is an inconvenience that the welding equipment must be changed every time the shape of the pack case 20 is changed.

[0012] Therefore, there is a need for a new solution that can minimize deformation of the battery modules even when swelling occurs in each battery module housed in the pack case, and there is a need for a new method that can fix the auxiliary partition wall to the inside of the pack case by a method other than welding. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Korean Patent Publication No. 10-2018-0113906 Summary of the Invention [Problem to be solved by the invention]

[0014] Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to install an auxiliary partition wall while minimizing welding inside a battery pack.

[0015] Another object of the present invention is to provide a battery pack having a structure capable of suppressing the swelling phenomenon of the battery module housed therein.

[0016] Other objects and advantages of the present invention can be understood from the following description and become more apparent from the embodiments of the present invention. Also, it is easily understood that the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed. [Means for solving the problem]

[0017] According to the present invention, there is provided a battery pack accommodating a battery module including a cell stack in which a plurality of battery cells are stacked, the battery pack comprising: a base plate supporting a lower portion of the battery module; a pack case including a main partition wall coupled to a center of the base plate; a side wall coupled along an edge of the base plate; and an auxiliary partition wall having both ends coupled to the main partition wall and the side wall, respectively; and a long bolt member coupled to the pack case through the side wall and the auxiliary partition wall so that the auxiliary partition wall is coupled to the main partition wall and the side wall.

[0018] The length of the long bolt member may be longer than the distance between the main bulkhead and the sidewall.

[0019] The long bolt member may be connected to the main bulkhead through the sidewall and an auxiliary bulkhead connected to the sidewall.

[0020] The auxiliary bulkhead may include coupling holes formed through both ends of the auxiliary bulkhead, and the long bolt members may be threadably coupled to the auxiliary bulkhead by passing through the coupling holes.

[0021] The main partition wall includes an insertion groove formed corresponding to a position of a coupling hole of the auxiliary partition wall to be coupled thereto, and the side wall includes an insertion hole formed through the side wall corresponding to a position of a coupling hole of the auxiliary partition wall to be coupled thereto, and the long bolt member may pass through the insertion hole and the coupling hole and be inserted into the insertion groove to be screwed to the pack case.

[0022] The auxiliary barrier rib may include a plurality of coupling holes formed at predetermined intervals along a height direction of the auxiliary barrier rib.

[0023] The long bolt member is composed of a screw head and a screw shaft that extends from the screw head and has a circular cross section, and the screw shaft may include a male screw portion that includes a thread formed by rotating an outer edge.

[0024] The external threads may be formed on an end of the screw shaft.

[0025] The auxiliary partition may include a connection hole formed through both ends of the auxiliary partition, the main partition may include an insertion groove formed corresponding to the position of the connection hole of the auxiliary partition to be connected, the side wall may include an insertion hole formed through the side wall corresponding to the position of the connection hole of the auxiliary partition to be connected, and the connection hole may include an internal thread portion having threads that engage with the threads of the external thread portion at a position corresponding to the position of the external thread portion of the long bolt member inserted into the insertion groove.

[0026] The male thread portion may be formed at the boundary between the screw shaft and the screw head.

[0027] The auxiliary partition may include a connection hole formed through both ends of the auxiliary partition, the main partition may include an insertion groove formed corresponding to the position of the connection hole of the auxiliary partition to be connected, the side wall may include an insertion hole formed through the side wall corresponding to the position of the connection hole of the auxiliary partition to be connected, and the connection hole may include an internal thread portion having threads that engage with the threads of the external thread portion at a position corresponding to the position of the external thread portion of the long bolt member inserted into the insertion groove.

[0028] The male thread portion may include a first male thread portion formed at an end of the screw shaft, and a second male thread portion formed at a boundary between the screw shaft and the screw head.

[0029] The auxiliary partition may include a connection hole formed through both ends thereof, the main partition may include an insertion groove formed corresponding to the position of the connection hole of the auxiliary partition to be connected, the side wall may include an insertion hole formed through the side wall corresponding to the position of the connection hole of the auxiliary partition to be connected, and the connection hole may include a first female threaded portion formed with threads that engage with the threads of the first male threaded portion at a position corresponding to the position of the first male threaded portion of the long bolt member inserted into the insertion groove, and a second female threaded portion formed with threads that engage with the threads of the second male threaded portion at a position corresponding to the position of the second male threaded portion.

[0030] The auxiliary partition wall has a hollow structure and includes a connecting pipe formed to penetrate both ends of the auxiliary partition wall, and a rib connecting an outer surface of the connecting pipe to an inner surface of the auxiliary partition wall, and the connecting pipe may include a connecting hole therein.

[0031] The main partition wall includes an insertion groove formed corresponding to a position of a coupling hole of the auxiliary partition wall to be coupled thereto, and the side wall includes an insertion hole formed through the side wall corresponding to a position of a coupling hole of the auxiliary partition wall to be coupled thereto, and the long bolt member may pass through the insertion hole and the coupling hole and be inserted into the insertion groove to be screwed to the pack case. [Effects of the Invention]

[0032] According to the present invention, the auxiliary partition wall can be fixed while minimizing welding inside the battery pack.

[0033] In addition, according to the present invention, the strength of the auxiliary partition walls that separate the plurality of battery modules housed inside the battery pack and support the sides of the battery modules can be improved, thereby suppressing the swelling phenomenon of the battery modules. [Brief explanation of the drawings]

[0034] [Figure 1] 1 shows a pack case included in a conventional battery module and battery pack. [Figure 2] 1 is a perspective view of a pack case included in a battery pack according to a first embodiment of the present invention; [Figure 3] 1 shows a long bolt member. [Figure 4] FIG. 10 is a partially cutaway perspective view of an auxiliary partition wall into which a long bolt member is inserted. [Figure 5] This shows one of the auxiliary partition walls in the pack case of FIG. 2 in isolation. [Figure 6] This shows a part of the main partition wall and the side wall from which the auxiliary partition wall in FIG. 5 has been separated. [Figure 7] FIG. 2 is a cross-sectional view of the pack case. [Figure 8] 1 is a partially cutaway view of an auxiliary partition included in a battery pack according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of a pack case included in a battery pack according to a third embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a pack case included in a battery pack according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concepts of the terms to best describe his own invention.

[0036] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can replace them at the time of this application.

[0037] Furthermore, in the description of the present invention, if it is determined that a detailed description of related publicly known structures or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0038] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and therefore the shapes and sizes of components in the drawings may be exaggerated, omitted, or illustrated schematically for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0039] The present invention relates to a battery pack that houses battery modules including a cell stack in which a plurality of battery cells are stacked, and is characterized in that auxiliary partitions 140 that separate the battery modules are fixed using bolts inserted into the side of a pack case 100, thereby improving the lateral support force of the battery modules.

[0040] 2 to 7 relate to a battery pack according to a first embodiment of the present invention, FIG. 8 relates to a battery pack according to a second embodiment of the present invention, FIG. 9 relates to a battery pack according to a third embodiment of the present invention, and FIG. 10 relates to a battery pack according to a fourth embodiment of the present invention.

[0041] Hereinafter, the battery pack of the present invention will be described in detail with reference to the above drawings.

[0042] (First embodiment) FIG. 2 is a perspective view of a pack case 100 included in the battery pack according to the first embodiment of the present invention.

[0043] As shown in FIG. 2, the battery pack of the present invention includes a pack case 100 and a long bolt member 200 coupled to the pack case 100.

[0044] The pack case 100 is composed of a base plate 110 , a main partition wall 120 , a side wall 130 , and an auxiliary partition wall 140 .

[0045] The pack case 100 includes a plurality of module areas A in which battery modules are directly mounted, and the module areas A are defined by a main partition wall 120, a side wall 130, and an auxiliary partition wall 140.

[0046] The base plate 110 serves to support the lower portion of the battery module housed in the pack case 100 and corresponds to the bottom of the pack case 100 .

[0047] The main partition wall 120 divides the space above the base plate 110 into two large spaces, and serves to insert and protect the conductive wires used inside the pack case 100.

[0048] As shown in FIG. 2, the main partition wall 120 is coupled to the center of the base plate 110 and extends across the base plate 110 .

[0049] The side wall 130 serves to support and protect the outer surface of the battery module mounted on the base plate 110 .

[0050] The sidewall 130 is coupled along the edge of the base plate 110 as shown in FIG.

[0051] The auxiliary partition 140 serves to separate the pair of adjacent battery modules from among the plurality of battery modules mounted on the base plate 110 .

[0052] As shown in FIG. 2, both ends of the auxiliary partition 140 are connected to the main partition 120 and the side wall 130, respectively.

[0053] The auxiliary partition wall 140 is coupled to the main partition wall 120 at a predetermined interval along the longitudinal direction of the pack case 100 .

[0054] The auxiliary partition 140 of the present invention is characterized by being relatively easy to attach and detach from the pack case 100. That is, it can be stably fixed to the pack case 100 without using methods such as welding. More specifically, the auxiliary partition 140 can be connected to the main partition 120 and the side wall 130 by long bolt members 200.

[0055] FIG. 3 shows the long bolt member 200.

[0056] The long bolt member 200 is composed of a screw head 210 and a screw body 220 that is formed to extend from the screw head 210 and has a circular cross section.

[0057] The long bolt is coupled to the auxiliary partition wall 140 while the screw body 220 is inserted into the side of the pack case 100. Therefore, it is preferable that the length of the long bolt member 200 is longer than the distance between the main partition wall 120 and the side wall 130.

[0058] The screw shaft 220 may include an externally threaded portion 220P including threads T formed by rotating the outer edge.

[0059] In the long bolt member 200 included in the battery pack according to the first embodiment of the present invention, the male thread portion 220P is formed at the end of the screw body 220, as shown in FIG.

[0060] FIG. 4 is a partially cutaway perspective view of the auxiliary partition wall 140 into which the long bolt member 200 has been inserted.

[0061] As shown in FIG. 4, the auxiliary partition wall 140 includes a connecting hole 141 drilled along the longitudinal direction of the auxiliary partition wall 140, and the long bolt member 200 passes through the connecting hole 141 of the auxiliary partition wall 140.

[0062] The long bolt member 200 inserted into the auxiliary partition 140 not only serves to fix the auxiliary partition 140 at a specific position in the pack case 100 but also to improve the strength of the auxiliary partition 140. Specifically, the battery module accommodated in the module area A shown in FIG. 2 may experience swelling due to an abnormality during charging and discharging. At this time, the auxiliary partition 140 supporting the side of the battery module may be subjected to high stress by the expanding battery module.

[0063] The auxiliary partition 140 of the present invention may have improved mechanical resistance to lateral stress that may be generated by the battery module due to the long bolt member 200 inserted therein.

[0064] FIG. 5 shows one of the auxiliary partition walls 140 in the pack case 100 of FIG. 2 in isolation.

[0065] 5, the auxiliary partition wall 140 includes connecting holes 141 formed through both ends thereof, and the long bolt member 200 can be threadedly connected to the auxiliary partition wall 140 by passing through the connecting holes 141. More specifically, the long bolt member 200 can be inserted into the main partition wall 120 by passing through the side wall 130 and the auxiliary partition wall 140 so that the auxiliary partition wall 140 can be connected to the side wall 130 and the main partition wall 120.

[0066] The auxiliary partition wall 140 may include at least one or more coupling holes 141 , and in this case, a plurality of long bolt members 200 corresponding to each coupling hole 141 may be coupled to the auxiliary partition wall 140 .

[0067] FIG. 6 shows a part of the main partition wall 120 and the side wall 130 from which the auxiliary partition wall 140 in FIG. 5 has been separated.

[0068] As shown in FIG. 6, the side wall 130 includes an insertion hole 131 drilled corresponding to the position of the connecting hole 141 of the auxiliary partition 140 so that the long bolt member 200 can pass through.

[0069] 6, the main partition wall 120 includes an insertion groove 121 formed corresponding to the position of the coupling hole 141 of the auxiliary partition wall 140 so that the long bolt member 200 can be inserted therein.

[0070] Therefore, as shown in FIG. 5, the long bolt member 200 passes through the insertion hole 131 of the side wall 130 and the coupling hole 141 of the auxiliary partition wall 140 and is inserted into the insertion groove 121 of the main partition wall 120.

[0071] The long bolt member 200 can be threadably coupled to the auxiliary bulkhead 140 and the main bulkhead 120 .

[0072] The coupling hole 141 included in the auxiliary partition 140 includes a female threaded portion 141P having a thread formed thereon that engages with the thread T of the male threaded portion 220P at a position corresponding to the position of the male threaded portion 220P of the long bolt member 200 inserted into the insertion groove 121.

[0073] The insertion groove 121 has a screw thread formed along the inner peripheral surface.

[0074] It is preferable that the threads of the coupling hole 141 and the threads of the insertion groove 121 are continuous without being interrupted.

[0075] Therefore, the long bolt member 200 that penetrates the side wall 130 is inserted without resistance to a certain depth into the auxiliary partition 140, and at the position where the female thread portion 141P begins, the thread T of the male thread portion 220P rotates so as to engage with the thread of the female thread portion 141P, and is threadedly coupled and inserted into the insertion groove 121 of the main partition wall 120.

[0076] FIG. 7 is a cross-sectional view of the pack case 100 cut so that the insertion grooves 121, the insertion holes 131 and the coupling holes 141 of the main partition wall 120, the side wall 130 and the auxiliary partition wall 140 are visible.

[0077] 7, the insertion groove 121 of the main partition wall 120 and the insertion hole 131 of the side wall 130 are formed at positions facing each other, and the auxiliary partition wall 140 is coupled to the main partition wall 120 and the side wall 130 such that the coupling hole 141 is aligned with the insertion groove 121 and the insertion hole 131. The auxiliary partition wall 140 is fixed to the side wall 130 and the main partition wall 120 by passing through the screw shaft 220 of the long bolt member 200 inserted through the side wall 130.

[0078] The long bolt member 200 has threads T of the male thread portion 220P that engage with the threads formed in the insertion groove 121 of the main partition wall 120 and the female thread portion 141P on one side of the coupling hole 141 of the auxiliary partition wall 140 that is adjacent to the main partition wall 120, thereby simultaneously screwing together the main partition wall 120 and the auxiliary partition wall 140.

[0079] It is preferable that the maximum diameter of the threads T included in the male thread portion 220P is smaller than the diameter Db of the thread body 220 so that there is no resistance in the process of the long bolt member 200 penetrating the side wall 130 and the auxiliary partition wall 140 before being screwed into the auxiliary partition wall 140 and the main partition wall 120. In this case, the diameters of the threads included in the insertion groove 121 and the female thread portion 141P of the coupling hole 141 are formed to correspond to the diameter Dt of the threads T of the male thread portion 220P.

[0080] The battery pack of the present invention may further include an upper cover coupled to the pack case 100 to cover an upper portion of each battery module accommodated in the pack case 100.

[0081] The upper cover is a well-known technology, and therefore a detailed description thereof will be omitted in the present invention.

[0082] (Second embodiment) The battery pack according to the second embodiment of the present invention is different from the battery pack according to the first embodiment in that the auxiliary partition 140 has a hollow structure therein.

[0083] FIG. 8 is a partially cutaway view of an auxiliary partition 140 included in a battery pack according to a second embodiment of the present invention.

[0084] The auxiliary partition wall 140 includes a connection pipe 142 formed in the hollow interior thereof penetrating both ends of the auxiliary partition wall 140, and a connection hole 141 is formed inside the connection pipe 142 so that the long bolt member 200 can be passed through and connected.

[0085] Therefore, the cross section of the coupling pipe 142 preferably has a ring shape.

[0086] The auxiliary partition 140 included in the battery pack according to the second embodiment of the present invention is characterized by being lightweight due to its hollow structure and having strength similar to that of the auxiliary partition 140 included in the battery pack according to the first embodiment.

[0087] The auxiliary partition 140 may include a rib 143 connecting the outer surface of the connecting pipe 142 and the hollow inner surface of the auxiliary partition 140 .

[0088] The ribs 143 serve to fix the connecting pipe 142 within the hollow interior of the auxiliary partition wall 140 and also to transmit the rigidity of the long bolt member 200 inserted into the connecting pipe 142 to the outer surface of the auxiliary partition wall 140. Therefore, the mechanical strength of the hollow structured auxiliary partition wall 140 can also be improved by the configuration of the ribs 143.

[0089] (Third embodiment) The battery pack according to the third embodiment of the present invention differs from the battery pack according to the first embodiment in that the male thread portion 220P of the long bolt member 200 is formed at the boundary between the screw body 220 and the screw head 210.

[0090] FIG. 9 is a cross-sectional view of the pack case 100 included in the battery pack according to the third embodiment, in which the insertion grooves 121, the insertion holes 131, and the coupling holes 141 of the main partition 120, the side wall 130, and the auxiliary partition 140 are cut so as to reveal them.

[0091] Due to the structure of the long bolt member 200 as described above, the long bolt member 200 is simply inserted into the insertion groove 121 of the main partition wall 120 and is substantially screw-coupled to the side wall 130 and the auxiliary partition wall 140 .

[0092] The coupling hole 141 includes a female thread portion 141P having threads formed thereon that engage with the threads T of the male thread portion 220P at a position corresponding to the position of the male thread portion 220P of the long bolt member 200 inserted into the insertion groove 121.

[0093] The insertion hole 131 has a screw thread formed along its inner circumferential surface.

[0094] It is preferable that the threads of the coupling hole 141 and the threads of the insertion hole 131 are not interrupted but are formed so that the threads are continuous.

[0095] Therefore, the long bolt member 200 that penetrates the side wall 130 is inserted without resistance to a certain depth into the auxiliary partition 140, and when the male threaded portion 220P contacts the insertion hole 131 of the side wall 130, the thread T of the male threaded portion 220P rotates to engage with the thread of the insertion hole 131, and is threaded and inserted into the female threaded portion of the connection hole 141 included in the auxiliary partition 140.

[0096] In the long bolt member 200, it is preferable that the diameter Db of the threaded body 220 is smaller than the maximum diameter of the thread T included in the male threaded portion 220P so that there is no resistance to movement of the threaded body 220 excluding the male threaded portion 220P before it passes through the side wall 130 and the auxiliary partition wall 140. In this case, the diameters of the threads included in the female threaded portion 141P of the insertion hole 131 and the coupling hole 141 are formed to correspond to the diameter Dt of the thread T of the male threaded portion 220P.

[0097] (Fourth embodiment) The battery pack according to the fourth embodiment of the present invention differs from the battery pack according to the first embodiment in that the male threaded portion 220P of the long bolt member 200 is formed at the end of the screw body 220 and at the point where the screw body 220 contacts the screw head 210.

[0098] That is, the male thread portion 220P includes a first male thread portion 220P1 formed at the end of the screw shaft 220 and a second male thread portion 220P2 formed at the boundary between the screw shaft 220 and the screw head 210.

[0099] FIG. 10 is a cross-sectional view of the pack case 100 included in the battery pack according to the fourth embodiment, in which the insertion grooves 121, the insertion holes 131, and the coupling holes 141 of the main partition 120, the side wall 130, and the auxiliary partition 140 are cut so as to reveal them.

[0100] Due to the structure of the long bolt member 200 as described above, the long bolt member 200 is screwed to the main bulkhead 120, the side wall 130 and the auxiliary bulkhead 140 at the same time.

[0101] The coupling hole 141 includes a female thread portion 141P having threads formed thereon that engage with the threads T of the male thread portion 220P at a position corresponding to the position of the male thread portion 220P of the long bolt member 200 inserted into the insertion groove 121.

[0102] That is, the coupling hole 141 includes a first female thread portion 141P1 and a second female thread portion 141P2 corresponding to the positions of the first male thread portion 220P1 and the second male thread portion 220P2 of the long bolt member 200 inserted into the insertion groove 121 of the main partition wall 120.

[0103] The first female thread portion 141P1 includes a thread that meshes with the thread T of the first male thread portion 220P1 at a position corresponding to the position of the first male thread portion 220P1 of the long bolt member 200 inserted into the insertion groove 121.

[0104] The second female thread portion 141P2 includes a second female thread portion 141P2 having a thread formed thereon that engages with the thread T of the second male thread portion 220P2 at a position corresponding to the position of the second male thread portion 220P2 of the long bolt member 200 inserted into the insertion groove 121.

[0105] The insertion hole 131 and the insertion groove 121 each have a screw thread formed along the inner circumferential surface.

[0106] It is preferable that the threads formed on the first female thread portion 141P1 and the threads of the insertion groove 121 are not interrupted and are formed so that the threads are continuous, and it is preferable that the threads formed on the second female thread portion 141P2 and the threads of the insertion hole 131 are not interrupted and are formed so that the threads are continuous.

[0107] Therefore, the long bolt member 200 that penetrates the side wall 130 is inserted without resistance to a certain depth into the auxiliary partition 140, and when the first male threaded portion 220P1 contacts the first female threaded portion 141P1 of the connection hole 141 and the second male threaded portion 220P2 contacts the insertion hole 131 of the side wall 130, the threads T of the first male threaded portion 220P1 and the second male threaded portion 220P2 rotate to engage with the threads of the first female threaded portion 141P1 and the insertion hole 131, and the screw body 220 including the first male threaded portion 220P1 is screwed into and inserted into the insertion groove 121 included in the main partition 120.

[0108] In the long bolt member 200, it is preferable that the diameter Db of the threaded body 220 is smaller than the maximum diameter D2 of the thread T included in the second male threaded portion 220P2 so that there is no resistance to movement of the threaded body 220 excluding the second male threaded portion 220P2 before it passes through the side wall 130 and the auxiliary partition wall 140. In this case, the diameter of the thread included in the second female threaded portion 141P2 of the insertion hole 131 and the coupling hole 141 is formed to correspond to the diameter D2 of the thread T of the second male threaded portion 220P2.

[0109] In addition, it is preferable that the maximum diameter D1 of the threads T included in the first male thread portion 220P1 is smaller than the diameter Db of the screw body 220 so that the screw body 220 including the first male thread portion 220P1 can be inserted into and coupled to the insertion groove 121 of the main partition wall 120 and the first female thread portion 141P1 of the coupling hole 141. In this case, the diameter D1 of the threads included in the insertion groove 121 and the first female thread portion 141P1 of the coupling hole 141 is formed to correspond to the diameter of the threads T included in the first male thread portion 220P1.

[0110] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, so it should be understood that there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0111] 10: (Prior Art) Battery Module 11: (Prior Art) End Plate 12: (Conventional technology) Module frame 20: (Conventional technology) Pack case 21: (Prior Art) Base Plate 23: (Conventional) Main bulkhead 24: (Prior Art) Auxiliary bulkhead Aw: (conventional technology) welded area 100: Pack case 110: Base plate 120: Main bulkhead 121: Insertion groove 130: Side wall 131: Insertion hole 140: Auxiliary bulkhead 141: Connection hole 141P: Female thread 141P1: First female thread 141P2: Second female thread 142: Combined pipe 143: Rib 200: Long bolt material 210: Screw head 220: Screw body 220P: Male thread 220P1: First male thread 220P2: Second male thread A: Module area T: Thread Dt: thread diameter D1: Diameter of the thread (first male thread part) D2: Diameter of the thread (second external thread) Db: Body diameter

Claims

1. A battery pack accommodating a battery module including a cell stack in which a plurality of battery cells are stacked, a pack case including a base plate supporting a lower portion of the battery module, a main partition wall coupled to a center of the base plate, a side wall coupled to an edge of the base plate, and an auxiliary partition wall having both ends coupled to the main partition wall and the side wall, respectively; a long bolt member that penetrates the side wall and the auxiliary partition and is connected to the pack case so that the auxiliary partition is connected to the main partition and the side wall.

2. The battery pack according to claim 1 , wherein the length of the long bolt member is longer than the distance between the main partition wall and the side wall.

3. The battery pack according to claim 1 , wherein the long bolt member is coupled to the main bulkhead through the sidewall and an auxiliary bulkhead coupled to the sidewall.

4. The auxiliary barrier rib includes a coupling hole formed through both ends of the auxiliary barrier rib, The battery pack according to claim 1 , wherein the long bolt member passes through the coupling hole and is screw-coupled to the auxiliary partition wall.

5. The main barrier rib includes an insertion groove formed corresponding to a coupling hole of the auxiliary barrier rib to be coupled thereto, the sidewall includes an insertion hole formed through the sidewall in a position corresponding to a coupling hole of the auxiliary barrier rib to be coupled; The battery pack according to claim 4 , wherein the long bolt member passes through the insertion hole and the coupling hole, is inserted into the insertion groove, and is screw-coupled to the pack case.

6. The battery pack of claim 4 , wherein the auxiliary partition comprises a plurality of coupling holes formed at predetermined intervals along a height direction of the auxiliary partition.

7. The long bolt member has a screw head and A screw body extending from the screw head and having a circular cross section; The battery pack according to claim 1 , wherein the screw body includes an externally threaded portion including a thread formed by rotating an outer edge.

8. The battery pack according to claim 7 , wherein the external thread portion is formed on an end of the screw body.

9. The auxiliary barrier rib includes a coupling hole formed through both ends of the auxiliary barrier rib, The main barrier rib includes an insertion groove formed corresponding to a coupling hole of the auxiliary barrier rib to be coupled thereto, The side wall includes an insertion hole formed through the side wall corresponding to a position of a coupling hole of the auxiliary barrier rib to be coupled, 9. The battery pack of claim 8, wherein the connection hole includes an internal thread portion having threads that engage with the threads of the external thread portion of the long bolt member inserted into the insertion groove at a position corresponding to the position of the external thread portion of the long bolt member inserted into the insertion groove.

10. The battery pack according to claim 7 , wherein the external thread portion is formed at a boundary between the screw shaft and the screw head.

11. The auxiliary barrier rib includes a coupling hole formed through both ends of the auxiliary barrier rib, The main barrier rib includes an insertion groove formed corresponding to a coupling hole of the auxiliary barrier rib to be coupled thereto, the sidewall includes an insertion hole formed through the sidewall in a position corresponding to a coupling hole of the auxiliary barrier rib to be coupled; 11. The battery pack of claim 10, wherein the connection hole includes an internal thread portion having threads that engage with the threads of the external thread portion of the long bolt member inserted into the insertion groove at a position corresponding to the position of the external thread portion of the long bolt member inserted into the insertion groove.

12. The male thread portion is a first male thread portion formed at an end of the screw shaft; The battery pack according to claim 7 , further comprising: a second external thread portion formed at a boundary between the screw shaft and the screw head.

13. The auxiliary barrier rib includes a coupling hole formed through both ends of the auxiliary barrier rib, The main barrier rib includes an insertion groove formed corresponding to a coupling hole of the auxiliary barrier rib to be coupled thereto, the sidewall includes an insertion hole formed through the sidewall in a position corresponding to a coupling hole of the auxiliary barrier rib to be coupled; 13. The battery pack of claim 12, wherein the coupling hole includes: a first female threaded portion having threads that engage with the threads of the first male threaded portion at a position corresponding to a position of a first male threaded portion of the long bolt member inserted into the insertion groove; and a second female threaded portion having threads that engage with the threads of the second male threaded portion at a position corresponding to a position of a second male threaded portion.

14. The auxiliary partition wall has a hollow structure and includes a connecting pipe formed to penetrate both ends of the auxiliary partition wall, and a rib connecting an outer surface of the connecting pipe to an inner surface of the auxiliary partition wall, The battery pack according to claim 1 , wherein the coupling tube includes a coupling hole therein.

15. The main barrier rib includes an insertion groove formed corresponding to a coupling hole of the auxiliary barrier rib to be coupled thereto, the sidewall includes an insertion hole formed through the sidewall in a position corresponding to a coupling hole of the auxiliary barrier rib to be coupled; The battery pack according to claim 14 , wherein the long bolt member passes through the insertion hole and the coupling hole, is inserted into the insertion groove, and is screw-coupled to the pack case.

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